Hand Tumors 01-22 Flashcards

1
Q

A 65-year-old woman presents with a slow-growing mass of the hand. Incisional biopsy shows a metastatic tumor. Which of the following is the most likely primary tumor location in this patient?

A) Breast
B) Colorectal
C) Kidney
D) Lung
E) Thyroid

A

The correct response is Option D.

Although smaller case series may show some variability, larger reviews on this topic have been quite consistent. Lung is the most common source of metastasis to the hand, representing 34% of all metastases reported in the most recent large review. Taken together, gastrointestinal tract tumors (esophagus, stomach, and colorectal) are in second place, comprising 25% of the total. Kidney (10%) and breast (5%) round out the top four. Thyroid tumors represent only 2% of metastatic tumors to the hand.

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2
Q

A 33-year-old man presents with a 2-year history of a 4-mm reddish discoloration underneath the left index fingernail. He reports significant tenderness to pressure directly on the discoloration, but not the surrounding tissue, along with pain in the area that is worse when going outside in the winter and reaching for items in the freezer. A photograph is shown. Which of the following is the most likely etiologic factor in the origin of this patient’s mass?

A) Arthritis at the distal interphalangeal joint
B) Capillary malformation
C) Growth of myoarterial unit
D) Proliferation at the germinal matrix
E) Trauma to the nail bed

A

The correct response is Option C.

The most likely etiologic factor involved in the origin of this mass is growth of myoarterial unit.

This patient has evidence of a glomus tumor, which is a rare benign tumor that often presents in the subungual region. Glomus tumors arise from the glomus body, which is a myoarterial unit that functions in thermoregulation. Clinical findings include focal tenderness and cold intolerance.

Some tests for glomus tumor include the Love pin test, Hildreth test, and cold-sensitivity test. In the Love pin test, pressure is applied to the area with a pinhead and the area containing the glomus tumor becomes exquisitely painful. In the Hildreth test, pain in the area is relieved by the use of a tourniquet, due to the restricted blood supply. In the cold-sensitivity test, cold water or an ice cube elicits increased pain in the affected area.

Diagnosis of glomus tumor can be verified with MRI or ultrasonography. Management consists of surgical excision of the lesion, as shown in the photograph.

Arthritis at the distal interphalangeal joint can give rise to digital mucous cysts, which can demonstrate nail deformity but typically are not painful.

Capillary malformation can result in reddish-appearing vascular tumors, but these would not typically present the sensitivity and cold intolerance seen in glomus tumors.

Proliferation at the germinal matrix can give rise to nail abnormalities, but these typically manifest as abnormalities in the nail plate rather than in the subungual region (i.e., melanonychia, skin cancers).

Trauma to the nail bed can result in subungual hematoma, which can cause pain, but a hematoma typically will resolve and not persist for years.

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3
Q

A 35-year-old man undergoes excision of a peripheral nerve sheath tumor from the median nerve of the left wrist. Careful dissection is performed, and the encapsulated tumor is removed uneventfully with complete preservation of motor and sensory function. Pathologic studies show a benign tumor. Which of the following is the most likely tumor type in this patient?

A) Clear cell sarcoma
B) Fibroma
C) Intraneural perineurioma
D) Neurofibroma
E) Schwannoma

A

The correct response is Option E.

Peripheral nerve sheath tumors are relatively uncommon and can present with pain or with motor/sensory deficits in the involved nerve. The majority of peripheral nerve sheath tumors are benign, and the most common benign tumor is a schwannoma. These are well encapsulated, slow-growing tumors comprised of Schwann cells. These usually can be removed without significant disruption of adjacent intact nerve fascicles or significant impact on patient function. Malignant nerve sheath tumors are less common but are more likely to have motor or sensory deficits at the time of presentation.

Neurofibromas are the second most common nerve tumor in the hand. They are distinct from schwannomas in that they involve nerve fascicles. Nerve repair or reconstruction may be required after resection. While the overwhelming majority are solitary, the presence of multiple neurofibromas raises suspicion for underlying neurofibromatosis which carries a high risk for malignant degeneration.

Fibromas are rare benign hand tumors. Dermatofibromas generally present as firm, flesh-colored nodules.

Clear cell sarcoma is a rare soft-tissue sarcoma which occurs most often in the extremities. Its predominant histopathologic feature is the source of its name. These tend to arise from tendons.

Intraneural perineurioma is a benign neoplasm of the peripheral nerve sheath that typically affects teenagers and young adults and tends to result in a motor-predominant neuropathy. It comprises up to 5% of neural tumors. Treatment typically requires resection and repair or grafting.

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4
Q

A 13-year-old girl presents with an enlarging mass on the right hand. The patient’s mother reports that the child has always had a bruised-appearing birthmark on the hand, but the region started enlarging in the last year. The patient reports aching pain mainly associated with exercise. On examination, the mass increases in size with dependence. A photograph, an x-ray study, and MRI images are shown. Which of the following is the most likely diagnosis?

A) Arteriovenous malformation
B) Hemangioma
C) Lymphatic malformation
D) Port-wine stain
E) Venous malformation

A

The correct response is Option E.

Vascular anomalies are divided into tumors and malformations. Hemangiomas are a classic example of a vascular tumor. Malformations are present at birth and grow with age. Vascular malformations don’t regress with age. They may not be obvious at a young age and become more evident as the patient ages or goes through hormonal changes such as puberty and pregnancy (if female). Other reasons for enlargement include trauma, infection, and thrombosis. Vascular malformations are secondary to an error in the morphogenesis of blood vessels, and they don’t enlarge secondary to cellular hyperplasia. There is a normal rate of endothelial cell turnover.

Vascular malformations are characterized by rate of flow and type of predominant tissue in the malformation. Slow-flow vascular malformations include capillary malformations, venous malformations (VMs), and lymphatic malformations (LMs). Fast-flow vascular malformations include arteriovenous malformations (AVMs) or fistulas. Combined vascular malformations aren’t uncommon. Most vascular anomalies can be diagnosed by history and clinical examination. However, medical imaging has become an important component for diagnosis and treatment planning.

This patient presents with a vascular malformation based on history, examination, and MRI. The subtype for this patient is consistent with a venous malformation based on findings of phleboliths (blood clots that become hardened and calcified) on MRI and x-ray. VMs are the most common type of vascular malformation. These malformations may be present in all tissue planes but, when present at the subcutaneous level, give the skin a purplish hue that is accentuated with gravity position of the limb. VMs are traditionally compressible, and the purplish hue and fullness of the mass will frequently diminish with limb elevation against gravity. Painful clots and phleboliths are commonly identified and may be sources of pain causing acute presentation. Patients may report chronic aching pain, swelling, and stiffness that is worse in the morning. Phleboliths demonstrated on imaging are pathognomonic for VMs. VMs of the extremity can be associated with undergrowth or overgrowth.

Ultrasonography, MRI, and catheter angiography are frequently used imaging studies to delineate the rate of flow, identify features, and evaluate the extent of malformation. X-ray study or CT scan may be used to assess bony involvement/bony deformation and may show phleboliths appearing as rounded, lamellated calcifications. Ultrasonography with Doppler scan is frequently the first-line imaging study; it can assess the rate of flow (delineate fast/slow flow), depth of the mass, and any feeding vessels. Compressibility of the mass can also be assessed. An ultrasound of a VM usually shows a sponge-like collection of vessels and compression; then release will show inflow of blood into the cavity. Phleboliths, ectatic/dilated vessels, and thickened overlying tissue can all be shown on ultrasonography. MRI of VMs show multilocular, lobulated, septated masses. These are hypo/isointense on T1-weighted sequences and hyperintense on T2 sequences. VMs can be shown to involve nerves, tendons, muscles, joints, and adjacent organs. Phleboliths can also be appreciated on MRI as low-signal regions/flow voids.

The other options wouldn’t be the most correct diagnosis for this patient. Hemangioma would be present at birth and grow rapidly (and regress for an involuting hemangioma). An AVM is a high-flow lesion and wouldn’t have phleboliths on imaging. An LM is a low-flow lesion and similarly wouldn’t demonstrate phleboliths. Neither an AVM nor an LM would appear to have increased size/congestion with dependence. Port-wine stain or capillary malformation is a flat macular cutaneous malformation and wouldn’t be characterized by this patient’s findings or imaging.

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5
Q

A 45-year-old patient has a slowly growing mass along the flexor sheath of the index finger at the level of the distal interphalangeal joint. The mass does not transilluminate and appears multinodular. It shows generally decreased signal intensity on both T1- and T2-weighted MRI. Which of the following surgical procedures is most likely to be recommended?

A) Distal interphalangeal level amputation and lymph node biopsy
B) Incisional biopsy
C) Marginal excision
D) Radical excision

A

The correct response is Option C.

The patient most likely has a giant cell tumor of the tendon sheath. This is a benign nodular tumor that is found on the tendon sheath of the hands. It is also known as pigmented villonodular tumor of the tendon sheath. It is the second most common soft-tissue tumor seen in the hand, following ganglion cyst. There are no known cases of metastasis of this tumor in the literature. The operative treatment is marginal excision, and literature reports a 5 to 50% recurrence rate, more common if the tumor extends into the joints and deep to the volar plate. Local recurrence is usually treated by repeat excision.

Incisional biopsy does not remove the entire tumor and is usually done for diagnosis, not treatment. A radical excision and amputation removes normal structures surrounding the tumor and will lead to unnecessary loss of function.

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6
Q

Which of the following histologic findings is most characteristic of giant cell tumor of the tendon sheath?

A) Histiocytoid mononuclear cells
B) Lymphocytic infiltration
C) Myofibroblasts
D) Spindle cells
E) Zones of necrosis

A

The correct response is Option A.

The giant cell tumor of tendon sheath (GCTTS) is the most common benign neoplasm in the hand after the ganglion cyst. It is a slowly growing, usually painless benign lesion of soft tissues. The tumor affects individuals between the ages of 30 and 50 years old and is found more often in women than men. Histologically, it is composed of multinucleated giant cells, histiocytes, fibrotic material, and hemosiderin deposits. Histiocytoid mononuclear cells are the neoplastic component and should always be present on pathologic evaluation of these lesions. Surgery is the main treatment option, but the tumor has a propensity for local recurrence. If untreated, or if the tumor continually recurs, these tumors can result in damage and degeneration of surrounding tissues or structures.

Lymphocytic infiltration, zones of necrosis, spindle cells, and myofibroblasts are not histologic components of GCTTS.

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7
Q

A 32-year-old woman presents with intermittent severe pain of the left ring fingernail that has worsened over the past several years. X-ray studies of the finger show no abnormalities. Which of the following findings on physical examination is consistent with a diagnosis of glomus tumor in this patient?

A) Pain decreases from pinpoint pressure on the nail
B) Pain decreases with inflation of a blood pressure cuff
C) Pain increases in warm temperatures
D) Pain increases only at night

A

The correct response is Option B.

A glomus tumor is a small benign mass containing cells from the glomus apparatus. Most (75%) are found in the hand and most of these (65%) are found in the fingertip. Tumors tend to be intermittent but quite painful. The classic triad of symptoms for a glomus tumor of the fingertip is 1) sensitivity to cold, 2) paroxysmal pain (day or night), and 3) pinpoint pain (Love’s sign). If a blood pressure cuff is inflated proximally, then pain will diminish in the fingertip (Hildreth’s sign). The diagnosis is usually confirmed with an MRI, and treatment is excision. Recurrence rates can be up to 20%.

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8
Q

A 17-year-old boy presents with a mass of the left forearm that has been enlarging over the past 3 months. A photograph is shown. Biopsy of the mass is consistent with spindle cell sarcoma. MRI shows a well-encapsulated mass that does not infiltrate neurovascular structures. CT scan of the chest shows no evidence of metastatic lesions. Which of the following is the most appropriate next step in management?

A) Amputation at the midforearm
B) Chemotherapy only
C) Excision and chemotherapy
D) Excision and radiation therapy
E) Radiation therapy only

A

The correct response is Option D.

Soft tissue sarcomas are rare malignant tumors representing less than 1% of all malignancies, with only 25% occurring in the upper extremity. The diagnostic workup generally includes a biopsy, magnetic resonance imaging scan to assess the extent of the tumor and its relationship to adjacent structures, and a computed tomography scan of the chest. This combination allows for appropriate clinical staging of the patient. The role of sentinel lymph node biopsy in the workup of soft tissue sarcomas is controversial. Treatment consists of wide excision, primary reconstruction, and radiation therapy (adjuvant or neoadjuvant). The tumor must be completely removed with a cuff of normal tissue (at least 1 cm); violation of the tumor decreases 5-year survival from 87 to 47%. More than 90% of extremity sarcomas can be managed with a limb-sparing resection.

Chemotherapy is rarely indicated and is never used as the only treatment for soft tissue sarcoma. Primary amputation is considered when the tumor infiltrates major neurovascular structures and resection would result in the sacrifice of more than one major peripheral nerve. Additional indications for amputation include involvement of the interosseous membrane, advanced disease with extensive loss of functional tissues, and severe comorbidities limiting reconstructive options.

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9
Q

A 42-year-old man presents with a painful subungual glomus tumor of the index finger. Definitive treatment should consist of which of the following?

A) Chemotherapy
B) Complete surgical excision
C) External beam radiation therapy
D) Immunotherapy
E) Intralesional steroid injection

A

The correct response is Option B.

Glomus tumors include approximately 1 to 5% of soft tissue tumors of the hand. The majority are subungual. Presentation is typically a raised blue or pink nodule that can discolor or deform the nail. Love’s pin test is performed by applying pressure to the area with a pinhead, causing exquisite pain. Diagnosis can be aided with plain film and MRI. Treatment includes complete surgical excision. There is no role for radiation, chemotherapy, immunotherapy, or steroid injections in definitive treatment.

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10
Q

A 35-year-old woman presents for examination of a mass of the right volar radial wrist. The patient reports that the mass spontaneously appeared 6 weeks ago and occasionally gets bigger or smaller. On physical examination, the mass transilluminates. Which of the following joints is the most likely origin point of the mass?

A) Lunotriquetral
B) Metacarpotrapezial
C) Radioscaphoid
D) Scapholunate
E) Scaphotrapezial

A

The correct response is Option C.

Ganglia are benign soft tissue tumors that are most commonly encountered in the wrist but may occur in any joint.

Sixty to 70% of ganglion cysts are found in the dorsal aspect of the wrist and communicate with the joint via a pedicle. This pedicle usually originates at the scapholunate ligament but may also arise from a number of other sites over the dorsal aspect of the wrist capsule.

Thirteen to 20% of ganglion cysts are found on the volar aspect of the wrist, arising via a pedicle from the radioscaphoid, scapholunate interval, scaphotrapezial joint, or metacarpotrapezial joint, in that order of frequency. Neither dorsal nor volar ganglion cysts typically originate from the lunotriquetral ligament.

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11
Q

A 66-year-old man presents with a mass along the ulnar margin of the index finger proximal phalanx. The patient reports that over the past year, the mass has grown in size. Physical examination shows the mass is now interfering with digital flexion. X-ray studies show bony erosion into the cortex of the middle phalanx. Excisional biopsy demonstrates a tan, multilobulated mass that has surrounded the digital nerve and invaded the bone cortex. Which of the following is the most likely diagnosis in this patient?

A) Chondrosarcoma
B) Epidermal inclusion cyst
C) Giant cell tumor of tendon sheath
D) Retinacular cyst
E) Schwannoma

A

The correct response is Option C.

Giant cell tumors of the tendon sheath are the second most common hand masses. They are slow-growing and painless, and affect the volar surfaces of the index, middle and ring finger, at the PIP or DIP joints. They usually appear tan or yellow, lobulated, and well-circumscribed. Bony erosion secondary to long-standing pressure may be observed on x-ray studies. Treatment is excision, with recurrence rates ranging from 0 to 44 percent. High recurrence rates are associated with satellite lesions, poor encapsulation, distal locations, intraosseous involvement, concurrent degenerative joint disease, or involvement of the adjacent joint/tendon. Radiotherapy following surgical excision has shown recurrence rates as low as 4 percent.

Schwannomas are benign peripheral nerve tumors derived from Schwann cells, that can involve the nerves of the hand. They are well encapsulated and slow growing, and typically arise over flexor surfaces. They present as a soft, nontender mass that is mobile and may cause associated paresthesias. Magnetic resonance imaging may be helpful to evaluate for malignant characteristics. These tumors can often be shelled out because they involve the nerve sheath instead of individual fascicles, with little risk of postoperative neurologic deficits. Malignant transformation is rare. Epidermal inclusion cysts are painless, firm, keratin-filled cysts developing from traumatic implantation of epithelium into the subcutaneous tissue. Typical locations include the volar palm and digits. No risk of malignant transformation has been reported, but cortical destruction can be observed, raising suspicion for a neoplastic process. There is a low rate of recurrence with surgical excision. These masses can be differentiated from giant cell tumors of the tendon sheath, in that they are cystic structures filled with keratin and not mutilobulated, solid masses.

Ganglions are usually solitary and occur in specific locations in the hand and wrist. The most common ganglion locations are the dorsal and volar wrist regions. They also occur in the digital flexor tendon sheath (retinacular cyst), arising from the A1 pulley. There is no consensus regarding the preferred treatment of a flexor tendon sheath ganglion. Historically, the large number of therapeutic options described suggests that a predictable treatment approach could not be agreed upon. Recent literature indicates that there are two acceptable treatment options: cyst aspiration or surgical excision.

Chondrosarcomas are the most common primary malignant bone tumors of the hand, most frequently affecting the proximal phalanx. They may arise de novo or from malignant transformation of benign cartilaginous lesions such as enchondromas. At imaging, it may often be difficult to distinguish chondrosarcomas from their benign chondroid counterparts such as enchondromas. Phalangeal chondrosarcomas are locally aggressive and, unlike chondrosarcomas of other skeletal structures, rarely metastasize.

Cortical breakthrough, irregular cortical thickening, and a soft-tissue component are all suggestive of chondrosarcoma rather than benign tumors such as enchondroma. Recurrence rates with intralesional excision are historically high, such that wide excision or amputation had previously been the mainstay of surgical treatment. Recent literature, however, advocates intralesional excision with close follow-up for low-grade lesions or phalangeal tumors in circumstances where amputation will result in significant functional loss. No role for irradiation or chemotherapy has been described.

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12
Q

A 48-year-old man presents with a painless mass on the left wrist that has been enlarging gradually over the past year. Physical examination shows a 5-cm mass at the wrist flexion crease, deep to the flexor carpi radialis. The mass is firm, smooth, and nonadherent to surrounding structures. The patient denies numbness, and no motor deficits in the median nerve distribution are noted. Tinel sign is present at the site of the mass. Plain-film x-ray studies show no abnormalities. On MRI, a homogeneous mass is noted within the median nerve. Which of the following is the most likely diagnosis?

A) Enchondroma
B) Lipoma
C) Neurofibroma
D) Radial artery aneurysm
E) Schwannoma

A

The correct response is Option E.

The most likely pathology of this mass is a schwannoma of the median nerve. These benign nerve tumors are typically painless proximal to the wrist. Schwannomas of the digits tend to be painful. Tinel sign can often be demonstrated. Nerve function typically is not disturbed. Because of the size and location, MRI is effective in characterizing and localizing the mass. With magnification, marginal excision of schwannomas is easily performed because they are almost self-extruding from the nerve. Compared with neurofibromas, schwannomas are noninfiltrative. The recurrence rate is approximately 4%. The risk of nerve deficit is higher for excision after recurrence.

An enchondroma would be apparent on a plain x-ray study and would reveal a mass with cortical thinning. A lipoma would likely be present within the carpal tunnel and would not be in continuity with the nerve. It is also unlikely to have positive Tinel sign. An aneurysm of the radial artery presents as a pulsatile mass. Vasospastic or thromboembolic findings may be present. The median nerve may be compressed by the aneurysm.

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13
Q

A 15-year-old boy is evaluated because of a 4-month history of a 2.5-cm, soft, well-circumscribed, tender dorsal mass of the right wrist. Examination shows the mass is well defined, does not transilluminate, and softens when the index and long finger are flexed. The image shown is obtained at the time of operative excision. Which of the following is the most likely diagnosis?

A) Anomalous extensor indicis proprius insertion
B) Extensor digitorum brevis manus
C) Fibrosarcoma
D) Giant cell tumor of tendon sheath
E) Multilobulated ganglion cyst

A

The correct response is Option B.

The extensor digitorum brevis manus (EDBM) is a rare (2 to 3% incidence) anomalous muscle of the hand that may present similarly as a tender dorsal wrist mass distal to the radiocarpal joint about the distal edge of the extensor retinaculum. The clinical presentation can mimic a dorsal wrist ganglion cyst and many cases of EDBM were either initially misdiagnosed as or occurred concurrent with ganglion cyst. There are a number of clinical features that may aid in differentiating the anomalous EDBM from a dorsal ganglion. The pathologic EDBM more often presents in adults as pain and swelling following physical activity or manual labor. If bilateral, the dominant hand is more commonly symptomatic. Physical examination may show hardening of the mass with resisted index and long finger extension and softening with resting digital flexion as the muscle relaxes. Treatment is guided by symptom severity and patient preference and alternatives include rest and immobilization, surgical release of the fourth compartment alone, or fourth compartment release with complete muscle excision. Ganglion cyst does not appear solid and would transilluminate.

Giant cell tumor of tendon sheath is a common tumor in the hand but rarely grows this large and is yellow, not red, in appearance.

Anomalous insertion of the EIP is a rare source of dorsal wrist pain, but the mass seen here is not consistent with that diagnosis.

Fibrosarcoma is a possibility but that tumor usually invades the skin, is irregular in form, and does not change in firmness with finger flexion and extension.

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14
Q

A 62-year-old woman presents because of a 6-month history of a painless mass near the nail fold of the left index finger. The patient reports that clear thick drainage leaks intermittently from the nail fold. She is concerned about the appearance of the nail. A photograph is shown. On evaluation of this patient, which of the following additional studies in her workup is most appropriate?

A) Blood work
B) Culture of a drainage specimen from the nail fold
C) Diagnostic x-ray study of the finger
D) Incisional biopsy of the mass
E) MRI of the finger

A

The correct response is Option C.

This is a mucous cyst based on history and examination. Mucous cysts are cysts that arise from the distal interphalangeal joints. They are frequently associated with dorsal osteophytes secondary to osteoarthritis and x-ray studies are useful to establish the severity of osteophytes. X-ray views usually demonstrate osteophytes in proximity to the cyst. The cyst can decompress and clear viscous fluid can be seen. Pressure on the germinal matrix from an enlarging mucous cyst can cause nail grooving, which this patient demonstrates.

These masses are benign and do not require treatment. Aspiration and corticosteroid injection can be considered for nonsurgical treatment. The osteophyte is thought to be an inciting cause of the mucous cyst in these patients and should be removed when surgically treating these patients hence the utility of x-rays in evaluation of the patient. The cyst and stalk are traditionally removed as well.

MRI is unnecessary as clinical examination should be sufficient to establish the diagnosis.

Blood work and culture would be unable to establish a diagnosis.

Culture is sometimes necessary if there are signs of infection but there are no concerning signs or symptoms in this patient. Biopsy is helpful when clinical diagnosis is suspect, but unnecessary with this benign mass.

X-ray studies of this patient’s left hand (anteroposterior and lateral) are shown.

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15
Q

A 40-year-old man employed as a construction worker comes to the office because of a 3-month history of median nerve sensory distribution deficit. Diagnostic evaluation shows a mass located in the medial cord of the brachial plexus. Histology of the mass shows a malignant peripheral nerve sheath tumor. Metastasis is most likely found in which of the following organ systems?

A) Brain
B) Colon
C) Liver
D) Lung
E) Spine

A

The correct response is Option D.

For malignant peripheral nerve sheath tumors, metastasis occurs in about 39% of patients, most commonly affecting the lung. Malignant peripheral nerve sheath tumors commonly present as a soft-tissue mass arising from a large peripheral nerve such as the sciatic nerve or brachial plexus. There is usually motor and sensory deficit of the affected nerve. Demographics for solitary neurofibromas are 30 to 55 years, and neurofibromatosis are 20 to 40 years. Malignant peripheral nerve sheath tumors are sarcomas. They originate from peripheral nerves or from the nerve sheath, such as Schwann cells, perineural cells, or fibroblasts. Wide surgical excision is the mainstay of treatment, including the affected nerve. Radiation therapy is an integral part of treatment. Chemotherapy is usually not used except in larger, higher grade tumors.

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16
Q

A 44-year-old woman comes to the office because of a 3-month history of a painful subungual area of bluish discoloration. The patient reports severe pain when localized pressure is applied to the area, and cold water testing elicits severe pain. Which of the following is the most likely diagnosis?

A) Glomus tumor
B) Hemangioma
C) Hematoma
D) Melanoma
E) Pyogenic granuloma

A

The correct response is Option A.

Glomus tumors comprise approximately 1 to 5% of soft-tissue tumors of the hand. The majority are subungual. Presentation is typically a raised blue or pink nodule that can discolor or deform the nail. Love’s pin test is performed by applying pressure to the area with a pinhead, causing exquisite pain. Diagnosis can be aided with plain film x-ray and MRI. Treatment includes complete surgical excision. Hematoma, hemangioma, and pyogenic granuloma would less likely present with point tenderness and positive cold water test.

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17
Q

A 40-year-old man comes to the physician because of a 3-month history of pain and swelling over the proximal phalanx of the right index finger. He has no history of trauma. X-ray studies and MRI of the finger show an expansile osteolytic lesion of the proximal phalanx. Examination of a specimen obtained on biopsy confirms the diagnosis of giant cell tumor of the bone. Which of the following is the most appropriate staging test for this patient?

A) CT scan of the cervical spine
B) CT scan of the chest
C) MR arthrography of the wrist
D) MRI of the brain
E) Pulmonary function testing

A

The correct response is Option B.

This patient is presenting with a primary giant cell tumor of the proximal phalanx bone. Giant cell tumors of the bone are considered benign but locally aggressive tumors. Only 2 to 5% of giant cell tumors arise from the bones of the hand. These lesions have a 1 to 5% incidence of pulmonary metastases. The distal radius is the third most common site of giant cell bone tumor origin. Hand and distal radius tumors have higher rates of recurrence and metastasis. The lungs are the most common site of metastatic lesions and a CT scan of the chest is recommended as part of the diagnostic work-up.

The tumors are graded radiographically according to the Campanacci grading system. Grade I lesions are well-demarcated with an intact bony cortex. Grade II lesions show cortical expansion, and Grade III lesions show cortical destruction with soft-tissue extension. Grade I and II lesions can be treated with curettage and bone grafting. Adjuvant treatments such as phenol and liquid nitrogen have been recommended, but their efficacy has not been proven. Recurrence rates have been reported between 30 and 80% with this approach. Later stage tumors are treated with en bloc excision or amputation and reconstruction with vascularized or nonvascularized bone grafts. High rates of tumor recurrence are thought to be due to incomplete resection or late presentation at the time of diagnosis.

There is no specific added benefit for an arthrogram of the wrist in a tumor arising from the proximal phalanx as in this case. MR arthrography of the wrist, CT scan of the cervical spine, MRI of the brain, and pulmonary function testing are not typically used for staging giant cell tumor of the bone.

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18
Q

A 24-year-old man who works as a laborer comes to the office because of a 2-cm mass on the dorsum of each hand. MRI shows an anomalous muscle. Which of the following is the most likely structure?

A) Extensor digitorum brevis
B) Extensor digitorum longus
C) Extensor digitorum brevis manus
D) Extensor indicis proprius
E) Extensor medii proprius

A

The correct response is Option C.

The extensor digitorum brevis manus is an anomalous muscle of the hand, which typically presents as a tender dorsal wrist mass. Incidence in the general population is estimated to be 2 to 3%. Anatomically, this muscle classically originates from the proximal dorsal radiocarpal ligament and inserts into the index finger extensor mechanism. Diagnosis is characteristic on ultrasonography or MRI. Treatment should be directed to symptoms and may include rest, activity modification, fourth dorsal compartment release, and/or muscle excision.

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19
Q

A 44-year-old man comes to the office because of a palpable mass of the right dorsoradial distal forearm. The patient reports that the mass has been growing slowly over the past 2 years. On examination, the mass is nontender. Excisional biopsy shows the mass is well encapsulated and separates easily from within the fibers of the dorsoradial sensory nerve, as the nerve emerges from beneath the brachioradialis tendon. Which of the following cells is the most likely origin of this mass?

A) Adipose
B) Giant
C) Glial
D) Spindle
E) Tendon

A

The correct response is Option C.

The mass is most consistent with a neurilemmoma or Schwann cell tumor. These are benign, encapsulated tumors of the nerve sheath. Their cells of origin are glial, likely Schwann cells. These masses usually arise from the side of or from within the nerve. Symptoms can be vague and manifest as a dull ache or as symptoms consistent with nerve compression.

A lipoma derives from adipose cells, but these generally do not originate from the substance of the nerve. Tumors consisting of tenocytes are essentially unheard of, but giant cell tumors originate from the tendon sheath and are usually intimately involved with the tendon sheath and thus unlikely to be found within the fibers of a nerve.

Pathology of spindle cells which form muscle, are usually seen in the setting of sarcoma or carcinoma. In general, they are usually found in a subcutaneous, peritendinous, and intramuscular plane. They are taken with margins and are unlikely to shell cleanly out of their soft tissue of origin.

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20
Q

A 25-year-old postpartum woman comes to the office because of a painful mass of the left little finger. The patient reports that the swelling began during her teen years but enlarged rapidly and became painful during the third trimester of her recent pregnancy. Physical examination shows the mass is soft and compressible. The patient reports that the mass becomes firm if the hand is dependent. Which of the following is the most appropriate method of treatment in this patient?

A) Arterial embolization
B) Oral propranolol therapy
C) Pulsed-dye laser therapy
D) Surgical excision
E) Observation

A

The correct response is Option D.

In this patient, observation would be inappropriate. Small, painless lesions can be safely observed, but symptoms such as pain or loss of function warrant intervention. In this patient, who has a painful venous malformation, observation would be inappropriate. Pulsed-dye laser therapy provides effective treatment for cutaneous vascular lesions. Although the image does show a bluish discoloration over the lesion in the small finger, the skin is largely uninvolved. This venous vascular malformation represents a deeper lesion that would be unaffected by laser therapies directed at the skin. Surgical excision remains the mainstay for treatment of symptomatic low-flow vascular malformations such as this one. The patient description presents a classic picture (soft, compressible, swelling with dependency, rapid growth with hormonal changes). Sclerotherapy may be combined with surgical excision for larger or more diffuse lesions. In this patient, the small, localized lesion can be approached by surgical excision alone. Arterial embolization can decrease the size of high-flow vascular malformations and decrease blood loss during surgical excision. The presentation of this lesion is most consistent with a low-flow, venous malformation (soft, compressible, swelling with dependency). As there is no arterial feeding vessel, this lesion would not be amenable to arterial embolization. Propranolol would be appropriate treatment for infantile hemangioma but is not appropriate for venous malformation.

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21
Q

An otherwise healthy 30-year-old man is brought to the office because of a slow-growing mass on the volar base of the left ring finger. There is no history of trauma. The patient reports no pain or discomfort. Examination shows a 1.0-cm midline mass that is located immediately distal to the metacarpophalangeal flexion crease. The mass is firm, nonpulsatile, and does not transilluminate. The mass does not move with finger flexion or extension. X-ray study shows no abnormalities. Which of the following is the most likely diagnosis?

A) Digital lipoma
B) Fibrosarcoma
C) Ganglion cyst
D) Giant cell tumor of tendon sheath
E) Neurilemmoma

A

The correct response is Option D.

The clinical scenario describes a lesion that is midline and overlies the flexor tendon sheath. The two most likely diagnoses in this scenario are ganglion cyst and giant cell tumor of tendon sheath. Both of these lesions tend to present as a ball-like lesion as described. These entities are usually distinguished on the basis of a transillumination test: light will pass through the mass if it is a ganglion cyst (since it is fluid) and will not if it is a giant cell tumor (or other solid masses). Since light was not transmitted through this lesion, and given the characteristic and location of the lesion, it is most likely to be a giant cell tumor of tendon sheath. Fibrosarcoma is extremely unlikely and would almost never present as a midline spherical mass on the palmar surface of the finger. Neurilemmoma is a relatively rare neural tumor that arises from the nerve sheath; on the volar aspect of the finger, it would present more laterally in the path of the digital nerve. Digital lipoma can appear as a midline mass, but this entity is very uncommon.

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22
Q

A 35-year-old man comes to the office because of a painless enlargement of the right index finger for the past 6 months. An x-ray study is shown. Curettage of the lesion and grafting with demineralized bone matrix are planned. Which of the following is the most likely outcome of this procedure in this patient?

A) Distant metastasis
B) Local recurrence of the lesion within 2 years
C) Pathologic fracture and extension to surrounding soft tissue
D) Regional nodal metastasis
E) Uneventful healing without recurrence

A

The correct response is Option E.

Uneventful healing without recurrence is most likely in this patient. The bone lesion pictured in the x-ray is characteristic of an enchondroma. Enchondromas are benign chondrogenic tumors arising from aberrant cartilaginous foci within the medullary canal. Chondroblasts are thought to escape from the physis and proliferate in the metaphysis.

Enchondromas are the most common bone tumor found in the hand (approximately 90%). They are found mostly in the proximal phalanx, middle phalanx, and metacarpal. Enchondromas are benign, expansile, and locally destructive lesions. They are usually asymptomatic and discovered incidentally on radiographs taken for another reason. Pain is more frequently associated with a malignant tumor such as a chondrosarcoma or a pathologic fracture from cortical thinning. Typical radiographic features are a well-circumscribed, radiolucent lesion that may be expansile or purely lytic with popcorn stippled calcification.

Smaller asymptomatic lesions can be observed. Larger lesions that are potentially unstable or symptomatic are treated by curettage with or without bone grafting. Many authors recommend the addition of autologous or allograft bone following tumor excision. However, there are studies showing no benefit to adding bone graft or bone graft substitute. There is no consensus on the treatment of lesions involving a pathologic fracture. Stable fractures should be treated with immobilization and allowed to heal prior to treating the enchondroma secondarily. Unstable fractures can be safely treated with curettage and fracture fixation in a single stage.

Enchondromas are benign and complete resection is curative. Recurrence of a lesion after surgery may suggest that the lesion is actually a low-grade sarcoma. The risk of malignant transformation in a solitary enchondroma is approximately 1%.

Pathologic fractures are relatively common, especially in the hand. These occur with minor trauma when the lesion has resulted in significant cortical thinning but expansion of the tumor into the surrounding soft tissue does not occur.

The potential for malignant transformation is greatly increased in multiple enchondromatosis, such as Ollier disease and Mafucci syndrome. Ollier disease is a nonhereditary form of multiple enchondromatosis associated with skeletal dysplasia. Mafucci syndrome is characterized by multiple enchondromatosis and cutaneous hemangiomas. The risk of malignant transformation to chondrosarcoma or osteosarcoma in these cases is up to 30%. Low-grade chondrosarcomas have a low metastatic potential.

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23
Q

A 63-year-old woman comes to the office because of progressive pain of the right ring finger over the past 4 months. Physical examination shows the ring finger is held in a flexed position with the metacarpophalangeal and proximal interphalangeal joints each at a 45-degree angle. Tenderness over the palm with active digital flexion is noted. The patient reports that when she wakes in the morning, the ring finger is generally fixed in a flexed position, and she has to physically straighten the finger with her other hand. Over the past month, the finger has remained flexed. Medical history includes type 2 diabetes mellitus and hypertension. Which of the following is the most likely diagnosis in this patient?

A) Central slip rupture
B) de Quervain tendinitis
C) Digital stenosing tenosynovitis
D) Dupuytren contracture
E) Ulnar nerve compression at the elbow

A

The correct response is Option C.

Stenosing tenosynovitis, or trigger finger, is an inflammatory tendinopathy of the digital flexor tendons. It can present with pain, stiffness, and occasionally a mass in the palm. Long-standing stenosing tenosynovitis may occasionally lead to a flexion contracture of the finger after proper treatment is not performing. Dupuytren disease is a flexion contracture of the digits and palm due to contracture of the palmar fascia. Dupuytren disease is a progressive condition and the patient would not be able to passively extend her finger. de Quervain tenosynovitis is a tendinitis affecting the tendons of the first dorsal compartment resulting in pain over the dorsal wrist and thumb. Ulnar nerve compression at the elbow may affect the intrinsic muscles causing a claw deformity and contracture of the ring finger. Commonly, the little finger is also affected, and the patient would have symptoms of paresthesia or numbness in the ulnar innervated fingers. Central slip rupture would cause a Boutonnière deformity with flexion at the PIP and hyperextension at the DIP.

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24
Q

A 72-year-old man is referred for surgical treatment of a 3-cm, tender red mass on the left elbow. It developed spontaneously over the past 3 weeks, and has not improved with 10 days of oral cephalexin therapy. During incision and drainage, the mass is found to be filled with copious milky white fluid with white solid granules. Pathology shows crystal deposits in the fluid. In addition to wound packing, which of the following is the most appropriate therapy?

A) Colchicine
B) Doxorubicin
C) Fluconazole
D) Methotrexate
E) Vancomycin

A

The correct response is Option A.

This patient has gout and presents with a gouty tophus of the elbow. The red nodule over a joint with milky white fluid is diagnostic. The treatment of choice is an anti-inflammatory agent, and colchicine is the most common. Gout results from an imbalance in purine metabolism, resulting in uric acid crystal deposition in the joints. The great toe is most commonly affected, classically known as podagra. When these nodules occur in the upper extremity, it is easy to misdiagnose them as bacterial in origin. For unknown reasons, gout is more common in men and occurs more frequently after surgery of any type.

Vancomycin would be appropriate for a severe, systemic bacterial infection such as methicillin-resistant Staphylococcus aureus (MRSA). In this case, purulent drainage would be expected, rather than the milky fluid with granules that was encountered.

Fluconazole is an antifungal. Methotrexate is used to treat rheumatoid arthritis, not gout. Doxorubicin is an antineoplastic chemotherapy agent and would be used to treat a biopsy-confirmed cancer.

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25
Q

A 20-year-old man comes to the office because of an enlarging mass of the humerus. Examination of a specimen obtained on biopsy shows osteosarcoma. Which of the following locations is most likely metastatic in this patient?

A) Brain
B) Colon
C) Digit
D) Liver
E) Lung

A

The correct response is Option E.

The most common site of osteosarcoma metastasis is the lung. The tumor is most commonly found in the upper extremity proximal humerus. Osteosarcoma is the most common malignant bone tumor. It is most commonly found in childhood and rarely in the hands at that time. The incidence in the hand is 0.18%. In patients over 40 years of age, the proximal phalanx and metacarpals are involved.

Symptoms often begin 3 to 12 months prior to diagnosis and include pain and swelling. Radiographs show a sunburst pattern with periosteal elevation at Codman’s triangle. Treatment includes wide excision or amputation and neoadjuvant chemotherapy.

Malignant tumors of bone are rare, occurring in 1/5000 tumors.

26
Q

A 44-year-old, right-hand–dominant man comes to the office because of a painless deep mass on the dorsum of the dominant hand. Biopsy shows myxoinflammatory fibroblastic sarcoma. Which of the following factors is most associated with the need for flap coverage and local recurrence?

A) Digital involvement
B) Dorsal versus palmar location
C) Patient age
D) Transverse biopsy incision
E) Treatment with radiation therapy

A

The correct response is Option D.

Sarcomas are rare tumors in the hand. The dorsum and mid palm are most commonly involved. Tumor types are most commonly epithelioid, malignant fibrous histiocytoma, and synovial sarcoma. The performance of a “suboptimal” biopsy incision (using a site or incision that cannot be incorporated into a standard limb salvage incision or amputation flap) is predictive of the need for flap reconstruction and local recurrence. The other factors listed may encourage a plastic surgeon to consider flap coverage but are not predictive in large series. A transverse incision in the extremities is considered “suboptimal.”

The importance of this knowledge is that surgeons must carefully consider the placement of incisions and the use of inadequate excisions when approaching unknown hand masses.

27
Q

A 34-year-old woman comes for evaluation because of a 4-month history of pain in the fingers of the right hand. The pain is most severe in the ring finger and is exacerbated by exposure to cold temperatures. Physical examination shows a blue discoloration under the nail of the ring finger. Which of the following is the most likely diagnosis?

A) Cutaneous melanoma
B) Epidermal inclusion cyst
C) Giant cell tumor
D) Glomus tumor
E) Mucous cyst

A

The correct response is Option D.

Glomus tumors are benign neurovascular tumors. The glomus apparatus is believed to function as a thermoregulatory control mechanism. Glomus tumors generally are found in the hand, most commonly in the digit, and often in the fingertip. They are characterized by severe pain, especially with exposure to cold temperatures. Cold sensitivity can be evoked by placing the digit in an ice bath. Glomus tumors are well visualized on MRI using T-1 and T-2 weighted images. Ultrasonography may also be useful in identifying glomus tumors. Treatment for glomus tumors is complete surgical excision. Up to 25% of these tumors may have multiple lesions.

Malignant melanomas may be seen in the subungual area. These tumors usually are identified by a pigmented streak under the fingernail. These tumors are generally painless and often go unrecognized. A pigmented lesion under the nail should be biopsied if it does not resolve by 4 weeks.

Giant cell tumors are benign soft-tissue tumors. They are the second most common tumor in the hand. These tumors generally occur on the volar surface of the fingers and hand. They present as a firm, nodular, nontender mass.

Epidermal inclusion cysts are benign masses of the hand thought to be the result of implantation of the epithelial cells into the underlying soft tissue. They produce a painless mass. Treatment of these cysts is by marginal excision.

A mucous cyst is a term used to describe a ganglion cyst of the distal interphalangeal (DIP) joint. This is a misnomer because the cysts are not filled with a mucous material, but synovial fluid. The cyst may produce nail deformities. Pain may be associated with these cysts, and is caused by the underlying arthritis of the DIP joint.

28
Q

A 30-year-old woman comes to the office for consultation regarding a 2-year history of a slow-growing mass on the volar aspect of the left ring finger. The growth is adjacent to the distal interphalangeal (DIP) joint. Physical examination shows the mass is firm and cannot be transilluminated. The overlying skin is intact. Which of the following is the most likely diagnosis?

A) Desmoid tumor
B) Ganglion cyst
C) Giant cell tumor
D) Pyogenic granuloma
E) Vascular tumor

A

The correct response is Option C.

The mass described in this scenario is a giant cell tumor of the tendon sheath. These growths are common in adults younger than 50 years of age. These masses are slow-growing, firm, lobulated, and painless. Giant cell tumors are the second most common tumor of the hand, after ganglion cysts. Unlike ganglion cysts, giant cell tumors cannot be transilluminated. Moreover, they usually occur on the volar aspect of the hand, and bone invasion is not commonly seen. These characteristics are not true of vascular tumors, desmoids, or pyogenic granulomas.

29
Q

A 48-year-old right-hand–dominant man comes to the office for evaluation of a tender mass of the distal volar forearm. Tinel sign is positive at the site of the mass. MRI shows that the mass involves the median nerve. Biopsy of the mass confirms a malignant peripheral nerve sheath tumor. On the basis of these findings, this diagnosis is most likely associated with which of the following conditions?

A) Amyotrophic lateral sclerosis
B) Charcot-Marie-Tooth disease
C) Multiple sclerosis
D) Neurofibromatosis 1
E) Parkinson disease

A

The correct response is Option D.

The correct response is that neurofibromatosis 1 (NF1) is associated with malignant peripheral nerve sheath tumors (PNSTs).

The majority of “nerve tumors” are PNSTs. Schwannomas and neurofibromas are the most common.

Malignant soft-tissue tumors of the hand are very rare and constitute only 1 to 2% of hand tumors. Malignant PNSTs have a very low annual incidence of 0.001% in the general population, and between 2 and 5% in patients with NF1. The plexiform subtype of neurofibromas poses a substantial risk of malignant degeneration.

Amyotrophic lateral sclerosis, multiple sclerosis, Charcot-Marie-Tooth disease, and Parkinson disease are not commonly associated with malignant PNSTs.

30
Q

A 25-year-old man is evaluated because of a deep 6-cm, palpable mass to the mid-volar forearm. MRI is performed, but the diagnosis remains inconclusive. An initial diagnostic biopsy is planned. Which of the following is most appropriate during this procedure?

A) Avoidance of cautery
B) Leaving the biopsy site open with compressive dressings
C) Performance of an excisional biopsy
D) Placement of a skin crease transverse incision
E) Use of a tourniquet without Esmarch bandage

A

The correct response is Option E.

An open biopsy is done for forearm tumors that cannot be diagnosed as benign on clinical or radiographic grounds. For a large lesion, an incisional biopsy is performed to minimize the risk of surrounding surgical field tumor contamination. Wide undermining must be avoided.

The biopsy is done with a bloodless field and a tourniquet, but elevate the arm only for exsanguination without an Esmarch bandage. Obtain meticulous hemostasis before wound closure. Sutures are placed close to the wound edges to avoid additional tumor skin contamination.

While a transverse incision may provide a better cosmetic result, it may complicate limb-sparing surgery if pathology determines malignancy.

31
Q

A 7-year-old girl is brought for evaluation because of a 2-month history of an asymptomatic 1-cm mass over the volar radial aspect of the wrist. The parents note no history of trauma. On physical examination, the mass is not adherent to the skin but affixed to the deeper tissues. She has full range of motion of the wrist without signs of carpal instability. X-ray studies of the wrist show no abnormalities. MRI is consistent with a ganglion. There is no evidence of carpal ligamentous injury. Which of the following is the most appropriate next step in management?

A) Observation
B) Sclerotherapy
C) Closed rupture
D) Wrist arthroscopy
E) Surgical excision

A

The correct response is Option A.

The next step in management is a period of observation. Although there is no general consensus regarding the best treatment for pediatric ganglions, most prefer observation and splinting for asymptomatic wrist ganglions. In the literature, the majority of pediatric wrist ganglions will spontaneously rupture and resolve without intervention. The diagnosis of volar wrist ganglion has been made by history, physical examination, and MRI, making needle biopsy unnecessary. This mass is asymptomatic and there is no sign of carpal ligamentous injury on the x-ray study or MRI, therefore there is no surgical indication for excision or wrist arthroscopy.

Closed rupture is a trauma and antiquated therapy for ganglions. Sclerotherapy does not treat wrist ganglia.

32
Q

A 48-year-old woman comes for evaluation because of a 6-month history of an increasing mass on the right ring finger. She reports that a similar mass was removed from this location 2 years ago. Medical records show that the mass was solid and of a variegated tan-brown color. The pathology report identified foamy histiocytes and hemosiderin deposits. Physical examination today shows a firm, well-demarcated mass on the dorsal-ulnar aspect of the ring finger proximal phalanx. Skin is not adherent to the mass. A photograph is shown. This patient is at increased risk for which of the following?

A) Compromise of blood flow to the finger
B) Invasion of the underlying bone
C) Local recurrence or extension
D) Metastasis to the liver
E) Spread to the regional lymph nodes

A

The correct response is Option C.

This is a giant cell tumor of the tendon sheath.

Ganglion cysts are the most common tumor of the hand, but are cystic in character. Giant cell tumor of the tendon sheath (also called localized nodular synovitis, fibrous xanthoma, and pigmented villonodular tenosynovitis) is the second most common tumor, but it is the most common solid tumor affecting the hand. The hemosiderin deposits give the tumor its variable tan-brown appearance.

This tumor is noted to recur locally, particularly if incompletely excised. Giant cell tumors are not known to metastasize either distantly or to regional lymphatics. Whereas giant cell tumor of bone involves the bone itself, giant cell tumor of tendon sheath does not. This tumor is not known to invade or compromise the digital vessels and thus would not compromise blood flow to the digit.

33
Q

A 55-year-old woman comes to the office because of a 2-year history of a painless mass within the thenar eminence. Physical examination shows a soft, mobile, nontender mass that does not transilluminate. Which of the following is the most likely diagnosis?

A) Epidermal cyst
B) Ganglion
C) Giant cell tumor
D) Glomus tumor
E) Lipoma

A

The correct response is Option E.

Lipomas are one of the most common tumors of the body with 10 to 20% occurring in the hand and wrist. Lipomas are most frequently located in the thenar eminence followed by dorsal or volar sides of the digits. The female-to-male ratio is 2:1 and age range is third to sixth decade.

Epidermal cysts have a 2:1 male-to-female ratio with a peak incidence at age 39. They are located in the distal phalanges, usually palmar index and long.

Ganglions account for 50 to 70% of all benign hand tumors with a female-to-male ratio of 3:1. They usually occur in the second to fourth decade with locations being dorsal carpal, volar carpal, volar retinacular, and mucous cyst of the distal interphalangeal joints. Some superficial ganglions will transilluminate.

Benign giant cell tumors of the tendon sheaths have no sex difference, occurring between the fourth and sixth decade and are located in the digits, mostly volar index and long.

Glomus tumors account for only 1 to 5% of hand tumors. There is a 2:1 female-to-male ratio, usually occurring between ages 30 to 50, and the tumors are subungual 50% of the time.

34
Q

A 48-year-old man is evaluated for reconstruction after resection of a tumor of the distal radius. Physical examination shows a 10-cm defect of the metaphysis and shaft. Which of the following is the most appropriate source of bone for reconstruction?

A) Contralateral fibula
B) Contralateral radius
C) Humeral shaft
D) Medial femoral condyle
E) Osteodistraction of the ipsilateral radius

A

The correct response is Option A.

The preferred source of bone for such a long piece of bone reconstruction is the fibula microsurgical vascularized transfer. Another viable option, which was not listed, could be the iliac crest.

Other sources listed would not yield as much bone stock, nor would they offer sufficient bicortical bone to yield a stable reconstruction with rigid fixation, such as:

Contralateral radius (presumably with the radial vascular supply)

Humeral shaft (presumably with the posterior radial collateral vessels)

Medial femoral condyle (based on descending genicular vessels)

Thus, they would not be the preferred source, although they could all be transferred microsurgically.

Osteodistraction would not be the first line of treatment for this defect because of the length of bone transport necessary.

35
Q

A 3-year-old boy is brought to the office because of a 9 × 8 × 6-cm mass of the left side of the chest. His parents report that the mass has been present for 8 months and has grown rapidly for the past 3 months. MRI confirms that the mass is calcified, lobulated, originates from the fourth and fifth ribs, and encroaches into the chest cavity to lie adjacent to the left ventricle. Other smaller lesions are identified in the scapulae, clavicles, and ribs. CT scan is shown. Examination of the specimen obtained on biopsy of the largest legion shows osteochondroma. Which of the following is the most appropriate management at this time?

A ) Radiation therapy with adjuvant chemotherapy
B ) Radical resection with adjuvant chemotherapy
C ) Wide local excision, reconstruction, and adjuvant radiation therapy
D ) Wide local excision with reconstruction
E ) No intervention at this time

A

The correct response is Option D.

The lesion in the patient described is a giant calcified osteochondroma; more specifically, it is within the setting of multiple hereditary exostoses, given the multiple smaller lesions in other areas. The resected specimen is seen in the picture shown after wide local excision.

An osteochondroma is a cartilage-covered bony growth, or exostosis, that arises from a surface of a bone – in the scenario described, the fourth and fifth ribs. It is the most common bone tumor in children, may be solitary or multiple, and may arise spontaneously or as a result of previous trauma. An osteochondroma can arise in any bone that develops from endochondral ossification. Multiple osteochondromas may be hereditary with an autosomal dominant pattern (Bessel-Hagen syndrome or hereditary multiple exostoses), as in the scenario described. Malignant transformation of an osteochondroma occurs in 1 to 25% of patients, with the risk being greater in hereditary multiple exostoses.

Numerous complications are associated with osteochondromas, including mechanical effects and deformity, fracture, vascular compromise, neurologic sequelae, and overlying bursa formation. Treatment of solitary lesions should be individualized – patients with small asymptomatic or minimally symptomatic lesions, typical imaging findings, and no functional or mechanical impairment or progressive deformity should be observed regularly for the possibility of spontaneous regression or malignant transformation. Larger, or giant, symptomatic osteochondromas should be treated by wide bony resection and reconstruction of the defect.

There is no role for neoadjuvant or adjuvant chemotherapy or radiation therapy for this lesion.

36
Q

A 26-year-old man comes to the office after jamming the index finger of his nondominant left hand while playing baseball 2 days ago. He says he has been in pain since the incident occurred. Physical examination shows a shortened, radially deviated left index finger. X-ray study shows a well-defined radiolucent lesion in the diaphysis of the proximal phalanx with a displaced apex-volar fracture. Which of the following is the most appropriate initial treatment?

A ) Amputation of the finger at the metacarpophalangeal (MCP) joint
B ) Closed reduction and percutaneous pin fixation only
C ) Curettage of the mass, bone grafting, and percutaneous pin fixation
D ) Serial x-ray studies every 3 months
E ) Wide resection of the mass and bone grafting

A

The correct response is Option B.

Enchondromas are benign, cartilaginous lesions that are the most common primary bone tumors arising from the bones in the hand. Approximately 35% of all enchondromas arise in the hand, and enchondromas account for as many as 90% of bone tumors seen in the hand. The proximal phalanx is the most common site of involvement, followed by the metacarpal and middle phalanx. Enchondromas may be diagnosed as an incidental finding on x-ray study. Pathologic fractures may occur. Initial treatment is to stabilize the fractures.

Amputation of the finger is not indicated with this benign lesion. Subsequent operative treatment involves curettage of the lesion with bone grafting and fixation. Small enchondromas found incidentally in x-ray study can be followed with serial x-ray. Wide resection is not indicated given the clinical course of the lesion.

37
Q

A 36-year-old man comes to the office because of a 2-cm painless mass over the dorsum of the metacarpal of the index finger of the dominant right hand. A ganglion is suspected. The mass is excised with primary closure. Pathologic examination shows a high-grade epithelioid sarcoma with a single positive margin. After staging, which of the following is the most appropriate management?

A ) Aggressive curettage of the positive margin followed by high-dose adjuvant radiation therapy with no further treatment
B ) Amputation at the wrist
C ) High-dose adjuvant radiation therapy with close follow-up of the wound bed
D ) Wide local excision

A

The correct response is Option D.

The most common subtypes of soft-tissue sarcoma found in the hand include epithelioid sarcoma, synovial sarcoma, and malignant fibrous histiocytoma. It is not uncommon for them to be misdiagnosed initially and treated as benign tumors of the hand.

The mainstay of treatment of extremity sarcomas is wide local excision. Although preoperative and postoperative radiation therapy is often used as an adjunct to wide local excision, adjuvant radiation therapy is not an acceptable replacement for margin-free resection. Curettage is also inadequate to obtain appropriate resection margins and would, in fact, put the patient at risk for seeding of the donor wound bed with malignant cells.

Local control and survival have been shown to be comparable in patients treated with either primary amputation or limb salvage when presenting with sarcomas of the hand. Therefore, primary amputation at the wrist is virtually never indicated.

38
Q

A 65-year-old man is referred for treatment of biopsy-proven subungual verrucous carcinomas of the index and long fingers of the dominant right hand. Physical examination shows deformed, raised nail beds. X-ray study shows no bony involvement of the distal phalanx with tumor. Which of the following is the most appropriate management?

A) Amputation through the distal interphalangeal joint
B) Amputation through the proximal interphalangeal joint
C) Mohs micrographic excision with graft coverage
D) Ray amputation
E) Topical application of 5-fluorouracil

A

The correct response is Option C.

Verrucous-type squamous cell carcinoma of the fingernails commonly affects the index, long, and ring fingers. Significant studies have shown that the etiology is related to strains of human papillomavirus (HPV).

The presence of HPV in these tumors suggests the possibility of genital-digital spread as a mechanism of tumor genesis. HPV-associated digital squamous cell carcinoma is more likely to recur following surgical treatment than previously reported. This rate of recurrence greatly exceeds that for cutaneous squamous cell carcinomas in general and may be caused by residual postsurgical HPV. Mohs micrographic excision appears to improve tumor-free excision rates compared with standard excision and may preserve more uninvolved tissue. The rate of metastasis in verrucous squamous cell carcinoma, however, appears to be low.

Because there is no evidence of bony involvement, amputation is likely premature. Amputation would be a reasonable alternative in recurrent disease or if positive margins were to continue during Mohs micrographic resection. Topical treatment with 5-fluorouracil (5-FU, Efudex) is not an adequate treatment for this lesion.

39
Q

An otherwise healthy 40-year-old woman comes to the office because of an 8-month history of pain and discomfort in the ring finger of the nondominant left hand. She describes the pain as sharp and localized to the volar aspect of the distal finger. It occurs at various times during the day, including at her desk at work, and sometimes awakens her from sleep. It resolves within a few minutes regardless of position or maneuver. Physical examination shows point tenderness of the pulp of the digit. Motor and sensory examinations and an x-ray study suggest no abnormalities. Which of the following is the most appropriate next step to establish a diagnosis?

A) Allen test
B) Ice bath immersion
C) Nerve conduction studies
D) Tinel test

A

The correct response is Option B.

The patient described shows classic symptoms of a glomus tumor of the ring finger. Provocative tests such as cold stimulation or spraying the lesion with ethyl chloride will provoke symptoms. If this type of examination were to be negative, other tests would be recommended. However, a cold provocation test is a logical next step in the scenario described.

Glomus tumors, painful benign lesions that arise from the arteriovenous thermoregulatory glomus body, occur in the fingertip 65% of the time. Classically, they are solitary lesions from within the nail bed (50%). They also occur commonly within the soft tissues of the fingertip and present with no visible or palpable mass or discoloration, as in the scenario described. The pain tends to worsen progressively.

Nerve conduction studies are useful when the practitioner suspects either peripheral nerve compression or other peripheral nerve injury. The vignette specifically states that position is not a factor in pain relief, which would be a sign that the pain could be related to nerve compression. Also, the vignette states that motor and sensory exams of the hand are normal. Nothing above is significantly suggestive of nerve compression, and therefore nerve conduction studies is not the best answer.

The digital Allen test is appropriate when finger pain is thought to be caused by ischemia from embolic disease, thrombotic disease, vasospasm, or trauma. Nothing in the scenario described suggests these conditions.

Tinel and Phalen tests are effective provocative tests for compression neuropathies, particularly carpal tunnel. These tests are appropriate to perform in any hand examination, especially when compression neuropathy is suspected. However, this is not the best choice in the scenario described because the vignette does not suggest compression neuropathy. Negative Tinel and Phalen tests could be useful to establish a diagnosis, but only as a negative.

40
Q

A 67-year-old man comes to the office because of a mass over his left palm that has grown rapidly during the past month. He reports that the mass has bled several times, although he does not recall trauma. Physical examination shows a 5 × 8-mm, lobulated, reddish purple mass. A photograph is shown. Which of the following is the most likely diagnosis?

A) Hemangioma
B) Malignant melanoma
C) Merkel cell carcinoma
D) Pyogenic granuloma
E) Squamous cell carcinoma

A

The correct response is Option D.

Pyogenic granulomas are benign vascular tumors of unknown etiology. These lesions grow rapidly and can easily bleed with little or no trauma. Because of these characteristics, they are often confused with a malignancy. Although trauma is sometimes associated with these lesions, over three quarters of cases have no history of trauma or any other predisposing factor. They have also been associated with pregnancy. Their differential diagnosis includes malignancies such as basal or squamous cell carcinoma or malignant melanoma, as well as other vascular-type anomalies.

Treatment of pyogenic granulomas often consists of a shave removal and cauterization. For recurrent or large lesions, surgical excision is recommended.

Hemangiomas are benign, vascular tumors that occur in children, usually in the limbs or trunk. Despite their vascular origin, hemangiomas do not metastasize or undergo malignant transformation. With age, growth of hemangiomas will slow and in many cases regress by age 5 to 7 years.

Malignant melanomas represent one of the most aggressive forms of skin cancers. Generally, these are pigmented, although an amelanotic or melanotic variance may occur.

Merkel cell carcinomas are a rare, aggressive skin cancer usually appearing as a flesh-colored or bluish red nodule on the face, head, or neck. These appear mostly in elderly patients. Merkel cell carcinoma is of a neuroendocrine origin in the skin.

Squamous cell carcinomas are the second most frequent type of skin cancer. This type of lesion can be present on the hand, especially in patients with a history of radiation exposure. They generally present as a broad, flat lesion with the appearance of a scab. The most common areas for these are sun-exposed areas, such as the face and the back of the hand.

41
Q

A 44-year-old woman comes to the office because of a 2-year history of a painless mass in the volar aspect of the forearm that has been enlarging gradually. She has no history of skin lesions or neurologic symptoms. Physical examination shows a 1.5-cm mass that is mobile in a transverse direction. Light tapping over the mass results in tingling of the index and long fingers. MRI shows a well-circumscribed area of enlargement within the median nerve that is hyperintense on T2 imaging. Which of the following is the most appropriate management?

A) En bloc resection with nerve grafting
B) Excision with nerve preservation
C) Incisional biopsy
D) Percutaneous needle biopsy
E) Segmental resection with primary nerve repair

A

The correct response is Option B.

The most appropriate course of treatment is excision with microsurgical nerve preservation.

Neurilemoma (schwannoma) is the most common benign nerve tumor of the upper extremity. These tumors result from a proliferation of Schwann cells. Lesions often present on the flexor surface of the hand and forearm and are generally painless; however, they may sometimes be accompanied by paresthesia. In some cases, there may be neurologic deficits. Neurilemomas are typically mobile in a transverse direction but not longitudinally. On MRI, they appear isointense with muscle on T1-weighted images but are hyperintense to subcutaneous fat on T2 imaging.

These lesions typically shell out easily from the surrounding nerve. Careful dissection with microsurgical technique is advocated to preserve nerve function. In most cases, the tumors can be removed with a small risk of neurologic deficits. Recurrence is uncommon, and there are rare instances of malignant transformation.

Neurilemomas are to be distinguished from neurofibromas, which are benign nerve tumors arising within nerve fascicles that are difficult to excise. These may be seen in the setting of neurofibromatosis. In cases where the tumor is intimately intertwined with nerve fascicles, segmental resection of involved fascicles may be necessary, followed by nerve reconstruction. There is a greater chance of neurologic dysfunction after excision of neurofibromas.

En bloc resection with nerve grafting is also not necessary for the well-circumscribed neurilemoma. In the excision of neurofibromas that are intimately associated with the nerve, if functioning fascicles need to be sacrificed, nerve grafting can be used to bridge the gap. Incisional biopsy is usually not recommended, as the lesion can instead be completely excised in a single session. Biopsy of the lesion can result in scarring, making a subsequent attempt at resection more difficult. In tumors with a high suggestion of malignancy based on imaging studies or clinical behavior (ie, severe pain and progressive neurologic deficits), biopsy may be used to obtain a tissue diagnosis.

Percutaneous needle biopsy is generally not recommended because results typically will not affect the treatment plan, and it can result in scarring of the nerve and increase the chance of damage during resection. Needle biopsy may also result in neurologic defect or pain. Segmental resection with nerve repair is generally not necessary for neurilemomas because these lesions will typically shell out easily from the surrounding nerve. In the case of neurofibromas where fascicles are intimately intertwined with the tumor, resection of involved nerve fascicles may be necessary.

42
Q

52-year-old woman comes to the office because of a 9-month history of the nail deformity shown. Physical examination shows thinned skin overlying an eponychial mass. The finger is nontender to palpation. She is dissatisfied primarily by the appearance of the nail. Which of the following is the most appropriate initial step in management?

A) Excision of the mass under the eponychial fold
B) MRI of the finger
C) Nail bed reconstruction with a split toenail bed graft
D) Nail germinal matrix ablation
E) Oral administration of fluconazole for 12 weeks

A

The correct response is Option A.

The most appropriate treatment of the nail groove shown is excision of the mucous cyst (ganglion) that underlies the eponychial fold and is deforming the germinal matrix. After excision of the cyst, all grooving should improve, if not resolve completely.

MRI plays a role in the identification of glomus tumors of the finger. These tumors may arise deep to the sterile nail matrix. MRI of the lesion shown might define the ganglion cyst, but is not necessary for diagnosis and would add a substantial cost to the treatment.

Nail bed reconstruction with a split sterile matrix graft can be used to address nonadherent nail plates that occur secondary to loss of the sterile matrix. The photographs shown do not demonstrate any broad, white areas of the nail plate suggestive of detachment.

Ablation of the nail germinal matrix may be necessary when split or thin nails arise following trauma to the germinal matrix. In these settings, removal of the germinal matrix with permanent loss of the nail can provide a permanent solution to the nail deformity.

Oral fluconazole is useful for treatment of onychomycosis. Nails affected by fungal infection typically present with loss of luster, discoloration, and crumbling reflective of the nail’s brittleness. None of these findings are present in the scenario described.

43
Q

A 63-year-old woman who underwent a Mohs resection of a squamous cell carcinoma of the hand is scheduled to undergo reconstruction of a defect on her long finger. She underwent ultraviolet light treatment for eczema 54 years ago. A photograph of the defect is shown. Which of the following is the most appropriate course of action?

A) Construction of a second metacarpal artery flap
B) Full-thickness skin grafting
C) Occlusive dressing
D) Split-thickness skin grafting

A

The correct response is Option B.

Skin cancers are the most common cancers in the world. In the United States, half of all cancers are skin cancers. Most skin cancers are thought to be related to solar exposure. Squamous cell cancers of the hand are often related to environmental agents (eg radiation or therapeutic light treatment).

If viable peritenon is available, full-thickness skin grafting is the best reconstruction option for the patient described. Healing by secondary intention in this patient would lead to a flexion contracture of the finger. In a 60-year-old patient with viable soft tissue over the tendon, a local or regional flap would not be required. Both options add another surgical procedure and have a high risk of complication and stiffness. For palmar defects, a split-thickness skin graft does not provide acceptable, durable coverage.

44
Q

A 24-year-old woman comes to the emergency department after jamming her left thumb while playing basketball. An incidental finding on x-ray study of the hand is shown. Which of the following is the most likely diagnosis?

A ) Enchondromatosis

B ) Metachondromatosis

C ) Osteochondroma

D ) Solitary enchondroma

E ) Synovial chondromatosis

A

The correct response is Option D.

The lesion shown in the x-ray study is consistent with an enchondroma based on its classic pattern of calcifications with rings and arcs, intramedullary position, and proximal phalanx location. They may expand enough to cause endosteal scalloping of the cortex. Solitary enchondromas are the most common benign bony tumors. They have a predilection for the small bones of the hands and feet. Of these, approximately 50% are in the proximal phalanx, followed

in frequency by the metacarpal and middle phalanx. Enchondromas account for 12 to 14% of benign bone neoplasms and 3 to 10% of osseous neoplasms in general. They occur equally in men and women.

Solitary enchondromas are most frequently discovered in patients aged 20 to 40 years and often as incidental findings on x-ray studies, while enchondromatosis (Ollier disease) is more commonly discovered from birth to age 10 years. Metachondromatosis is a rare inherited disease associated with multiple enchondromas and osteochondromas. Osteochondroma is a cartilage-capped bony exostosis adjacent to the external surface of the bone and therefore not consistent with the x-ray study shown. Synovial chondromatosis is a rare condition where the synovial lining of a joint develops cartilage loose bodies. This does not occur within the bone.

45
Q

An 18-month-old boy is brought to the office because of a 3-month history of rapidly enlarging lesions on the long and ring fingers (shown). Examination of a specimen obtained on incisional biopsy of the lesion on the ring finger shows histology with interlacing fibroblasts and characteristic intracytoplasmic eosinophilic inclusion bodies. Which of the following is the most appropriate next step?

A ) Administration of acyclovir

B ) Distal finger amputations

C ) MRI

D ) Observation for spontaneous involution

E ) Wide excision of both lesions with full-thickness skin grafting

A

The correct response is Option E.

This is the classic appearance of infantile digital fibromatosis. Age at presentation can range from 5 months to 6 years. Lesions are rapidly growing, broad-based masses on the dorsal or lateral aspects of fingers. They have classic intracytoplasmic inclusion bodies in cellular tumors. They may be multiple with characteristic €œkissing € lesions.

Recommended treatment is complete wide excision and reconstruction, often with full-thickness skin grafting or coverage with a local flap. Inadequate resection leads to recurrence.

Acyclovir would be appropriate for herpetic whitlow, but not for this condition. It is inappropriate for children younger than 2 years. Safety and efficacy in children younger than 2 years have not been established.

Distal finger amputation is overly aggressive and unnecessary for this condition.

Despite the possibility of spontaneous regression in some cases, these tumors may cause finger deformities if observed and must be distinguished from fibrosarcoma. MRI is not helpful in distinguishing any better the extent of the tumor.

46
Q

A 45-year-old man comes to the office because of a 6-month history of a painless mass on the right distal forearm. Physical examination shows a well-circumscribed 6-cm mass. MRI of the chest, axilla, and forearm shows no other lesions. Examination of a specimen obtained on incisional biopsy shows epithelioid sarcoma. Which of the following is the most appropriate initial management?

A ) Chemotherapy

B ) Excisional biopsy

C ) Forearm amputation

D ) Radiation therapy

E ) Wide local excision

A

The correct response is Option D.

Preoperative radiation should be administered for epithelioid sarcomas, as it will help decrease tumor size and local recurrence rates. Chemotherapy is appropriate for tumors that are high grade, greater than 10 cm in diameter, involve the lymph node, or are metastatic. As chemotherapy plays an important role in epithelioid sarcomas, it is usually given postoperatively. Excisional biopsy is reserved for low-grade tumors. Epithelioid sarcomas are usually high grade, so excisional biopsy would not be appropriate. Forearm amputation should be considered if negative margins cannot be achieved. Wide excision with negative margins is a mainstay of surgical treatment.

47
Q

A 45-year-old man comes to the office because he has had a two-week history of persistent pain in the small finger after bumping it against a table. Radiographs are shown. Which of the following percentages best describes the likelihood of tumor recurrence after curettage and bone grafting in this patient?

A ) 10 B ) 25 C ) 50 D ) 75 E ) 90

A

The correct response is Option A.

The lesion represents an enchondroma, which is the most commonly found primary bone tumor in the hand. This benign tumor is thought to develop from fragments of cartilage near the central physis. The tumor is most common in the proximal phalanx, followed by the metacarpals and middle phalanx. Patients often present with finger pain following minor trauma that has resulted in the development of a pathologic fracture. Radiographically, enchondromas appear as well-defined areas of central lucency in the metaphyseal or diaphyseal portion of the bone. As the enchondroma grows, it frequently results in thinning and scalloping of the bone €™s cortex. Stippling and punctate calcifications may be seen within the areas of lucency.

The treatment for patients presenting with a pathologic fracture within an area involved with an enchondroma usually begins with a period of immobilization to allow for fracture healing; this may then be followed by surgery, most commonly open biopsy, curettage, and bone grafting. Recurrence following curettage is infrequent but occurs in 2% to 15% of patients. Because of this, patients should have periodic radiographic screening after surgery at six months, one year, and two years after initial surgery.

48
Q

A 45-year-old woman is evaluated for a two-year history of a slowly enlarging soft-tissue tumor of the right volar palm at the level of the distal palmar crease and the fourth metacarpophalangeal joint. Findings on MRI are highly suggestive of a soft-tissue malignancy. Which of the following is the most appropriate management?

A ) Excisional biopsy through a Brunner incision

B ) Incisional biopsy through a longitudinal incision

C ) Needle aspiration and touch preparation of specimen

D ) Preoperative chemotherapy followed by wide local excision

E ) Wide local excision followed by radiation therapy

A

The correct response is Option B.

The biopsy is the most important aspect of the evaluation of any hand tumor. The biopsy must be planned properly so that it does not make adequate wide local resection more difficult or impossible. The biopsy incision must be incorporated within the definitive resection; therefore, transverse or Brunner incisions would spread the tumor away from the primary, which could increase the incidence of local recurrence or prevent limb-preserving surgery.

In the scenario described, the scar should be parallel to the metacarpal, allowing it to be easily removed within the resection margins. One study suggested that ultimate survival may be compromised when the biopsy is performed at an institution other than the one providing definitive treatment.

MRI is the imaging technique of choice for evaluating soft-tissue neoplasm. In one study of 134 palpable masses in the hand, MRI demonstrated the cause of the masses in 94% of the cases. Despite the helpful information shown by MRI, soft-tissue biopsy is still mandatory to determine a definitive treatment plan.

Needle aspiration and touch preparation is not appropriate for soft-tissue malignancy of the hand. More substantial tissue is needed to evaluate potential sarcomas. Favorable results have been reported using core needle biopsy.

Wide local excision followed by radiation therapy and preoperative chemotherapy followed by wide local excision are not appropriate because definitive tissue biopsy is needed before radical surgery and chemotherapy are undertaken.

49
Q

A 57-year-old man has a painless mass on the right wrist that has been enlarging gradually over the past two years. Physical examination shows a 4-cm mass at the wrist level deep to the flexor carpi ulnaris. The mass is smooth and firm, is nonadherent to surrounding structures, and is not bony. Tinel sign is present at the site of the mass, but no ulnar nerve sensory or motor deficits are noted. Plain-film radiographs show no abnormalities. MRI shows a homogeneous mass within the ulnar nerve. Which of the following is the most likely diagnosis?

(A) Aneurysm of the ulnar artery

(B) Enchondroma

(C) Epidermal inclusion cyst

(D) Giant cell tumor of the tendon sheath

(E) Schwannoma

A

The correct response is Option E.

The most likely pathology of this mass is a schwannoma of the ulnar nerve. These benign nerve tumors are typically painless proximal to the wrist. Schwannomas of the digits tend to be painful. A Tinel sign can often be demonstrated. Nerve function typically is not disturbed. Because of the size and location, MRI is effective in characterizing and localizing the mass. With magnification, marginal excision of schwannomas is easily performed because they are almost self-extruding from the nerve. Compared with neurofibromas, schwannomas are noninfiltrative. The recurrence rate is approximately 4%. The risk of nerve deficit is higher for excision after recurrence.

An aneurysm of the ulnar artery presents as a pulsatile mass. Vasospastic or thromboembolic findings may be present. The ulnar nerve may be compressed by the aneurysm. Surgery will preclude thromboembolic events. If the digital brachial index is <0.7, arterial reconstruction is required.

An epidermal inclusion cyst results from implantation of epithelial cells into the underlying soft tissue or bone after an injury. Involvement of the thumb or index finger is most common. The cyst can abscess and require drainage. Otherwise, the cyst can be marginally excised from surrounding soft tissue or curettaged from bone. Interestingly, imaging of bony involvement can demonstrate cortical erosion or bone destruction that is more typical for malignancy.

A giant cell tumor of the tendon sheath is a rubbery mass that is more common along the flexor surfaces of the digits. The slowly enlarging tumor can compress or splay adjacent digital nerves and arteries. Recurrence is minimized with a complete marginal excision and bipolar cauterization of the tumor bed. The recurrence rate is reported to be 5% to 50%.

50
Q

A 37-year-old woman has had intermittent pain in the tip of the long finger of the dominant right hand during the past three years. She says the pain is excruciating and occurs randomly. She has extreme sensitivity to cold in the finger. Physical examination shows extreme tenderness of the central matrix of the long finger. Loupe magnification of the nail complex and finger pad shows no abnormalities. Which of the following is the most likely diagnosis?

(A) Buerger disease

(B) Epidermal inclusion cyst

(C) Glomus tumor

(D) Hemangiopericytoma

(E) Kaposi sarcoma

A

The correct response is Option C.

Glomus tumors occur most frequently in the fingertip. In the digit, most glomus tumors occur subungually. The digital pulp is a less common location. Symptoms of glomus tumors typically include pain, sensitivity to cold, and tenderness on palpation. On close evaluation, a blue €‘purple mass can sometimes be observed. The Love sign is extreme pain on direct, focal pressure. The Hildreth sign is ablation of pain with proximal tourniquet inflation. MRI can localize the glomus tumor.

The surgical approach is either direct transungual or lateral subperiosteal. Complete excision results in rapid resolution of symptoms. Recurrence varies from 6.6% to 33%. Incidence of nail deformity with the transungual approach is 3.3% to 10%.

Buerger disease or thromboangiitis obliterans (TAO) is an inflammatory, occlusive, and nonatherosclerotic vascular disease. The angiitis most commonly affects the small and medium €‘sized arteries, veins, and nerves. Tobacco use and development and progression of TAO are clearly linked. The precise etiology of TAO is unknown. The arteriographic findings include normal proximal arteries, absent atherosclerosis or emboli, and focal and multifocal distal segmental occlusions of small and medium €‘sized vessels, interspersed with normal €‘appearing segments. Irregular stenosis with corkscrew appearance is the classic arteriographic finding. Cessation of tobacco use is the critical first step in successful treatment.

An epidermal inclusion cyst develops after an injury traps epithelial cells in the underlying soft tissue or bone. These cysts slowly enlarge and typically are not painful. However, an epidermal inclusion cyst can abscess and require drainage.

Hemangiopericytoma is a rare tumor that can involve soft tissue or bone. Approximately 30% to 50% of cases develop in the limbs. It derives from vascular Zimmermann pericytes. These differ from glomus tumor and hemangioma. Biopsy is critical to diagnosis, and treatment involves functional wide local excision. The tumor can recur locally, and malignant forms can metastasize, primarily to the lung and skeleton.

There are several clinical types of Kaposi sarcoma (KS). Classic KS runs an indolent course over 10 to 15 years. Most cases are seen in elderly men of Italian or Eastern European Jewish ancestry. However, HIV-associated KS has a fulminant, disseminated, and most often fatal course. Other clinical forms of KS occur in recipients of renal allotransplantation, patients undergoing immunosuppressive therapy, prepubescent children, or young black African men. Recently, a gamma herpes virus €”human herpes virus type 8 (HHV-8) €”was identified in KS tissue from patients with classic, African, transplantation-related, and AIDS-associated KS.

51
Q

A 57-year-old man has a painless mass on the right wrist that has been enlarging gradually over the past two years. Physical examination shows a 4-cm mass at the wrist level deep to the flexor carpi ulnaris. The mass is smooth and firm, is nonadherent to surrounding structures, and is not bony. Tinel sign is present at the site of the mass, but no ulnar nerve sensory or motor deficits are noted. Plain-film radiographs show no abnormalities. MRI shows a homogeneous mass within the ulnar nerve. Which of the following is the most likely diagnosis?

(A) Aneurysm of the ulnar artery

(B) Enchondroma

(C) Epidermal inclusion cyst

(D) Giant cell tumor of the tendon sheath

(E) Schwannoma

A

The correct response is Option E.

The most likely pathology of this mass is a schwannoma of the ulnar nerve. These benign nerve tumors are typically painless proximal to the wrist. Schwannomas of the digits tend to be painful. A Tinel sign can often be demonstrated. Nerve function typically is not disturbed. Because of the size and location, MRI is effective in characterizing and localizing the mass. With magnification, marginal excision of schwannomas is easily performed because they are almost self-extruding from the nerve. Compared with neurofibromas, schwannomas are noninfiltrative. The recurrence rate is approximately 4%. The risk of nerve deficit is higher for excision after recurrence.

An aneurysm of the ulnar artery presents as a pulsatile mass. Vasospastic or thromboembolic findings may be present. The ulnar nerve may be compressed by the aneurysm. Surgery will preclude thromboembolic events. If the digital brachial index is <0.7, arterial reconstruction is required.

An epidermal inclusion cyst results from implantation of epithelial cells into the underlying soft tissue or bone after an injury. Involvement of the thumb or index finger is most common. The cyst can abscess and require drainage. Otherwise, the cyst can be marginally excised from surrounding soft tissue or curettaged from bone. Interestingly, imaging of bony involvement can demonstrate cortical erosion or bone destruction that is more typical for malignancy.

A giant cell tumor of the tendon sheath is a rubbery mass that is more common along the flexor surfaces of the digits. The slowly enlarging tumor can compress or splay adjacent digital nerves and arteries. Recurrence is minimized with a complete marginal excision and bipolar cauterization of the tumor bed. The recurrence rate is reported to be 5% to 50%.

52
Q

A 37-year-old woman has had intermittent pain in the tip of the long finger of the dominant right hand during the past three years. She says the pain is excruciating and occurs randomly. She has extreme sensitivity to cold in the finger. Physical examination shows extreme tenderness of the central matrix of the long finger. Loupe magnification of the nail complex and finger pad shows no abnormalities. Which of the following is the most likely diagnosis?

(A) Buerger disease

(B) Epidermal inclusion cyst

(C) Glomus tumor

(D) Hemangiopericytoma

(E) Kaposi sarcoma

A

The correct response is Option C.

Glomus tumors occur most frequently in the fingertip. In the digit, most glomus tumors occur subungually. The digital pulp is a less common location. Symptoms of glomus tumors typically include pain, sensitivity to cold, and tenderness on palpation. On close evaluation, a blue €‘purple mass can sometimes be observed. The Love sign is extreme pain on direct, focal pressure. The Hildreth sign is ablation of pain with proximal tourniquet inflation. MRI can localize the glomus tumor.

The surgical approach is either direct transungual or lateral subperiosteal. Complete excision results in rapid resolution of symptoms. Recurrence varies from 6.6% to 33%. Incidence of nail deformity with the transungual approach is 3.3% to 10%.

Buerger disease or thromboangiitis obliterans (TAO) is an inflammatory, occlusive, and nonatherosclerotic vascular disease. The angiitis most commonly affects the small and medium €‘sized arteries, veins, and nerves. Tobacco use and development and progression of TAO are clearly linked. The precise etiology of TAO is unknown. The arteriographic findings include normal proximal arteries, absent atherosclerosis or emboli, and focal and multifocal distal segmental occlusions of small and medium €‘sized vessels, interspersed with normal €‘appearing segments. Irregular stenosis with corkscrew appearance is the classic arteriographic finding. Cessation of tobacco use is the critical first step in successful treatment.

An epidermal inclusion cyst develops after an injury traps epithelial cells in the underlying soft tissue or bone. These cysts slowly enlarge and typically are not painful. However, an epidermal inclusion cyst can abscess and require drainage.

Hemangiopericytoma is a rare tumor that can involve soft tissue or bone. Approximately 30% to 50% of cases develop in the limbs. It derives from vascular Zimmermann pericytes. These differ from glomus tumor and hemangioma. Biopsy is critical to diagnosis, and treatment involves functional wide local excision. The tumor can recur locally, and malignant forms can metastasize, primarily to the lung and skeleton.

There are several clinical types of Kaposi sarcoma (KS). Classic KS runs an indolent course over 10 to 15 years. Most cases are seen in elderly men of Italian or Eastern European Jewish ancestry. However, HIV-associated KS has a fulminant, disseminated, and most often fatal course. Other clinical forms of KS occur in recipients of renal allotransplantation, patients undergoing immunosuppressive therapy, prepubescent children, or young black African men. Recently, a gamma herpes virus €”human herpes virus type 8 (HHV-8) €”was identified in KS tissue from patients with classic, African, transplantation-related, and AIDS-associated KS.

53
Q

A 26-year-old woman comes to the office for consultation regarding a painful mass in the right palm that has been enlarging over the past three years. She has had paresthesia of the hand and weakness of the thumb during this time. Gadolinium-enhanced MRI (shown) shows a high-flow arteriovenous malformation involving the thenar muscles, supplied mostly by the radial artery, and extending to the first and second metacarpals. Which of the following is the most appropriate initial management?
(A) Pulsed-dye laser therapy
(B) Ligation of the radial artery
(C) Embolization of the radial artery
(D) Selective intralesional embolization
(E) Surgical resection

A

The correct response is Option D.

This patient must be counseled that any surgical intervention could devascularize her hand or digits, due to postoperative vasospasm of the abnormal digital arteries. Ligation of the radial artery may result in transiently decreased flow to the arteriovenous malformation (AVM), but this lesion will almost certainly develop collaterals from the ulnar system and remain symptomatic. Surgical resection alone, even with the use of a tourniquet, may be technically very difficult with significant risk of injury to digital vessels or nerves. Selective embolization of the lesion, which is performed by an interventional radiologist, creates a window of opportunity for staged surgical resection, due to decreased flow to the AVM. Selective preoperative embolization may, in fact, be performed several times prior to surgical resection, for a complex or large AVM. Pulsed-dye laser therapy would not be helpful for deep, high-flow vascular malformations.

Preoperative photographs are shown below.

54
Q

A 30-year-old man is brought to the operating room for removal of a grade 2 fibrosarcoma on the right hand. He is otherwise healthy and currently takes no medications. Physical examination shows a 4 x 5-cm lesion on the dorsal aspect of the hand. Which of the following interventions is the most appropriate preparation for dissection of the lesion?
(A) Elevation of the arm for one minute and application of tourniquet pressure to 250 mmHg
(B) Exsanguination with an elastic bandage and application of tourniquet pressure to 200 mmHg
(C) Exsanguination with an elastic bandage and application of tourniquet pressure to 250 mmHg
(D) Compression of the brachial artery, elevation of the arm for one minute, and application of tourniquet pressure to 250 mmHg
(E) Compression of the radial and ulnar arteries, elevation of the arm for one minute, and application of tourniquet pressure to 250 mmHg

A

The correct response is Option D.

Exsanguination of the arm in patients with neoplastic tumors is not recommended due to the possibility of dissemination of tumor cells to other sites. The arm may be partially exsanguinated through elevation and compression of the brachial artery above the elbow for one minute. The tourniquet may then be inflated so dissection can proceed in a relatively bloodless field. Elevation of the arm alone has been found to be the least effective mechanism of exsanguination.

Tourniquet pressures have been shown to be adequate for dissection when they are approximately 50 to 75 mmHg greater than systolic pressure. Unnecessarily high tourniquet pressures may result in nerve injury and post-tourniquet paralysis. As a general rule in adults, most procedures can be performed with tourniquet pressures of 250 mmHg. In obese patients or in patients with significant hypertension or atherosclerotic disease, this may need to be increased to 300 mmHg. In this young patient, a pressure of 250 mmHg would suffice for surgery.

55
Q

A 20-year-old woman who is a competitive gymnast comes to the office for evaluation of a soft, subcutaneous mass on the volar-radial aspect of the right wrist (shown). She says the mass fluctuated in size until one month ago; since then, the mass has remained persistently prominent and associated with achy, intermittent discomfort in the wrist. Which of the following interventions is most likely to result in the lowest risk of recurrence of the mass?
(A) Rupture
(B) Injection
(C) Aspiration
(D) Incision
(E) Excision

A

The correct response is Option E.

This patient has a ganglion, the most common soft-tissue tumor of the hand, which is prevalent in women between the second and fourth decades of life. Volar wrist ganglia usually arise from either the radiocarpal joint or the capsule of the scaphotrapezial joint and are the second most common ganglion of the hand, representing approximately 20%; dorsal wrist ganglia account for 60% to 70% of hand and wrist ganglia and most often originate at the scapholunate ligament. Treatments are categorized as nonoperative and operative. The lowest recurrence rates are associated with complete surgical excision of the ganglion.

Nonoperative treatments include needle decompression or aspiration, rupture by digital pressure or other blunt external force (striking the mass with a large book, for example), and injection with corticosteroids, sclerosing agents, local anesthetics, or combinations of these solutions. These techniques may reduce the mass and alleviate symptoms with limited success for varying periods of time but are associated with higher rates of recurrence than surgical excision.

56
Q

A 70-year-old woman comes to the office for evaluation of a painless mass on the left ring finger involving the perionychium (shown) that has been enlarging rapidly over the past three weeks. She says that minor trauma causes the mass to bleed. Physical examination shows a fleshy, reddish, superficially purulent rash. Which of the following is the most likely diagnosis?
(A) Basal cell carcinoma
(B) Hemangioma
(C) Keratoacanthoma
(D) Pyogenic granuloma
(E) Squamous cell carcinoma

A

The correct answer is Option D.

Pyogenic granuloma is a reactive vascular tumor that rapidly grows in response to minor trauma. These tumors are somewhat friable and bleed easily. Treatment is usually excision with cauterization of the base. As with any tumor, pathology should be obtained to rule out less common tumors. Management options include chemical cauterization, curettage and cauterization, and formal excision.

Squamous cell carcinoma is not likely in view of the fact that the tumor arose within a three-week time period. Basal cell carcinoma is also unlikely because these are generally more erosive-appearing lesions that require a longer time interval than three weeks to develop to the size shown. Keratoacanthoma is also unlikely because these are keratotic-appearing lesions that usually have a central pore. Although these rapidly proliferate, they are not generally as friable or have the characteristic of easy bleeding. Keratoacanthomas are also sessile appearing. Hemangioma is also incorrect because a hemangioma developing in an elderly patient is unusual. Hemangioma should be included in the differential diagnosis of a rapidly proliferating vascular lesion in the neonatal period.

57
Q

A 63-year-old man who has been hospitalized for the past week after undergoing coronary artery bypass grafting has a pulsatile mass in the volar aspect of the right wrist. The nurse reports that an arterial catheter was recently removed from the radial artery. Which of the following is the most appropriate management of the mass?

(A) MRI of the wrist
(B) Application of a pressure dressing until the mass resolves
(C) Anticoagulation
(D) Replacement of the radial artery catheter
(E) Exploration and vascular repair

A

The correct response is Option E.

False or pseudoaneurysms result from an arterial wall penetration. The extravasated hematoma organizes and then recanalizes. The lumen of the false aneurysm will have endothelial lining. False aneurysms result from penetrating injuries and fractures, such as stab wounds, arterial catheterization fractures, or gunshot wounds. The treatment of a pseudoaneurysm is dependent on whether the radial artery is critical to hand perfusion. If the ulnar artery alone is adequate, the aneurysm can be ligated and excised. If the radial artery is critical to distal perfusion, the radial artery can be either directly repaired or reconstructed with a vein graft. Usually, the arterial defect is too large for primary repair of the artery. If the site becomes infected, the risk for arterial hemorrhage is significant.

True aneurysms occur after an injury that allows the vessel to gradually dilate. The true aneurysm is more uniform in shape and has an endothelial lining. True aneurysms result from repeated trauma (i.e., hypothenar hammer syndrome) or vessel diseases that weaken the wall.

MRI would provide detailed imaging of the lesion; Doppler ultrasonography would provide similar information more quickly. In an adult, compressive dressing can control bleeding but is not successful long term in resolving the pseudoaneurysm. One case in a child has been reported using ultrasound-directed compression. Anticoagulation would complicate bleeding from the pseudoaneurysm. Replacement of an arterial catheter could aggravate bleeding, compromise distal flow, or increase infection risk.

58
Q

A 30-year-old man has pain in the right wrist after falling on his outstretched right hand. Radiographs of the wrist show normal findings; a radiograph of the hand is shown above. Which of the following is the most likely diagnosis?

(A) Chondromyxoid fibroma
(B) Enchondroma
(C) Giant cell tumor
(D) Osteoid osteoma
(E) Osteosarcoma

A

The correct response is Option B.

The most likely diagnosis is enchondroma, a benign cartilaginous tumor that is the most common primary tumor of bone in the hand. Enchondromas typically develop during the second or third decade of life. Although they are often asymptomatic and discovered incidentally on imaging studies, as in this patient, pathologic fractures occurring in the
area of the tumor may lead to diagnosis. Pain in the absence of fracture is suggestive of malignant degeneration.
In patients with enchondromas, radiographs show a scalloped, lytic lesion within the medullary canal of the affected bone, occasionally with scattered calcification. Periosteal reaction is rare. Microscopic examination shows benign clusters of hyaline cartilage surrounded by lamellar bone with varying calcification.

Enchondromas that develop on the surface of the bone or within the cortex are known as periosteal or juxtacortical chondromas. Conditions associated with enchondroma include Ollier disease, or multiple enchondromatosis, and Maffucci syndrome, in which patients have multiple enchondromas associated with subcutaneous hemangiomas.
Appropriate management is curettage of the lesion. Bone grafting or use of a bone substitute may be required.

Chondromyxoid fibromas are benign cartilaginous tumors that rarely occur in the upper extremity. Radiographs show a radiolucent lesion with small sclerotic rims that separate the tumor from lamellar bone.

Giant cell tumors of bone are not common in the hand, wrist, or distal forearm. Only 2% to 5% of all giant cell tumors of bone occur in the hand; in contrast, the radius is the third most commonly affected site, with 16% of all giant cell tumors of bone occurring in this region. Management is controversial, as limited resection is associated with high recurrence rates locally, and more aggressive resection is likely to result in significant limitation of function.

Osteoid osteomas are symptomatic lesions. Affected patients have pain, especially at night, that is relieved with administration of nonsteroidal anti-inflammatory agents. Radiographs show a target-like lesion, illustrating the central nidus of the tumor within the bone.

Osteosarcomas are also rare in the hand. These malignant tumors exhibit varying degrees of bone erosion and periosteal reaction.

59
Q

A 67-year-old man has a mass overlying the metacarpal of the right index finger that has enlarged rapidly over the past six weeks. He underwent kidney transplantation for polycystic renal disease five years ago. Which of the following is the most appropriate management?

(A) Observation for spontaneous involution
(B) Electrodesiccation and curettage
(C) Interlesional injection of 5-fluorouracil
(D) Excisional biopsy and primary wound closure
(E) Excision and sentinel node biopsy

A

The correct response is Option D.

This 67-year-old man has a keratoacanthoma, a cutaneous lesion that appears similar to squamous cell carcinoma. Although keratoacanthomas had been thought previously to be benign, recent studies have suggested that this lesion
is actually a variant of squamous cell carcinoma. Keratoacanthoma first appears as a red papule on sun-damaged skin and expands rapidly over several weeks. Although most keratoacanthomas regress even without treatment, some can be aggressive and metastasize. Because these lesions have shown an affinity for immunosuppressed patients, an association has been suggested.

Excisional biopsy is most appropriate because the architecture of the lesion is important for accurate diagnosis. In this patient who has a keratoacanthoma affecting the right index finger, the wound can be closed primarily.

Observation for spontaneous involution is obviously inadequate and even dangerous in an immunocompromised patient with a keratoacanthoma because of the risk for aggressive tumor growth and metastasis.

Electrodesiccation and curettage and interlesional injection of 5-fluorouracil are not appropriate therapy in immunocompromised patients.

Sentinel node biopsy is excessive because the risk for lymphatic spread is low.

60
Q
A