Skin Lesions Flashcards
An obese 47-year-old man comes to the office for pain and drainage in the perineal region. A photograph is shown. Medical history includes hypertension, hypercholesterolemia, and diabetes. Which of the following is the most important factor in reducing the risk of recurrence after surgery?
A) Adjuvant radiation
B) Antibiotic therapy
C) Extent of resection
D) Intralesional corticosteroid injection
E) Method of closure
The correct response is Option C.
This patient has hidradenitis suppurative (HS). There are various surgical treatments available to these patients with varying risk of recurrence. Surgical options include incision and drainage, surgical deroofing, local excision, and radical resection of all involved tissue. Reconstructive and closure techniques include secondary healing, primary closure, skin grafting and locoregional pedicled flaps. Numerous studies have looked at the outcomes with various closure techniques and they show that risk of recurrence is likely influenced more by the extent of disease rather than the method of definitive closure. Because of the recurrent nature of this disease, surgery has been considered as the only effective curative therapy for HS. Inadvertent compromise in the margin of resection may diminish the probability of successful healing. Radical resection of all hair-bearing skin with a 1- to 2-cm clear margin of normal tissue is the gold standard and the most important factor in reducing risk of recurrence. Recurrence rates tend to be higher after excision in regions where functional and aesthetic outcomes take priority, and often limit the extent of resection and compromise the ability to obtain clear margins (ie, axilla, perineum, breast). Historically, low-voltage radiation was used as a treatment modality for HS and it is thought to cause complete follicular destruction. Current studies on radiotherapy as treatment for HS are very limited because of concern regarding malignancies arising in radiation fields. Radiation should be reserved for individuals with severely recalcitrant disease and used with extreme caution in younger individuals. Bacterial burden may also diminish the probability of successful wound healing. Topical and systemic antibiotics are still the mainstay treatment for mild HS. Despite their widespread use, few studies have shown their efficacy. In addition, antibiotics do offer relief by reducing the burden of abscesses and pustules in some individuals, but recurrence in these people is frequent. Standard practice of managing acute flares with intra-lesional steroid injections lacks clinical evidence. It has been shown in a series of patients to reduce erythema, edema, size and pain, but no effect on recurrence of disease has been shown.
2018
A 50-year-old woman is evaluated for multiple firm, nodular, pink-colored lesions of the scalp, ranging in size from 2 to 4 mm. Examination of a specimen obtained on biopsy shows benign cylindroma. Which of the following is the most appropriate management of these lesions?
A) Cryotherapy
B) Electrodessication and curettage
C) Imiquimod therapy
D) Radiotherapy
E) Surgical excision
The correct response is Option E.
Cylindromas are benign adnexal tumors showing an eccrine and an apocrine differentiation. They are found most commonly on the scalp and face, and are more common in women. Solitary cylindromas are generally sporadic in nature. Multiple cylindromas can be seen in patients with Brooke-Spiegler syndrome as an autosomal dominant trait with variable penetrance.
Cylindromas may undergo malignant transformation, and therefore surgical excision is typically recommended, with close postoperative follow-up given high recurrence rates.
Cryotherapy, electrodessication and curettage, and imiquimod are not treatments for cylindromas.
Radiotherapy has been used to treat malignant cylindromas (also known as cylindrocarcinoma or adenoid cystic carcinoma), but not benign cylindromas.
2018
A 56-year-old woman presents with a 1-cm primary superficial basal cell carcinoma on the left volar mid-forearm. Medical history includes renal transplantation, carcinoma of the right breast managed with lumpectomy and radiation, and treatment for a gunshot wound to the left forearm. The basal cell carcinoma is located within the previous traumatic scar. Which of the following clinical features is an indication for Mohs micrographic surgery in this patient?
A) Basal cell carcinoma arising in traumatic scar
B) History of radiation
C) Immunocompromised status of patient
D) Size of basal cell carcinoma
E) Superficial basal cell carcinoma
The correct response is Option A.
The clinical feature in this particular patient that fulfills the criteria to get Mohs micrographic surgery is that the basal cell carcinoma is arising in a traumatic scar. There are many clear indications for Mohs micrographic surgery for basal cell carcinoma: certain size, histology, and anatomic location, all recurrent basal cell carcinomas, and the occurrence of basal cell carcinoma in irradiated skin, traumatic scars, areas with osteomyelitis/chronic ulceration/inflammation, and/or patients with genetic syndromes. Almost all primary basal cell carcinomas in the H and M zones, regardless of pathology (i.e. superficial, nodular, or aggressive), size, or health status of the patient, are candidates for Mohs micrographic surgery. In the L zone, most basal cell carcinomas are also candidates for Mohs micrographic surgery (except all superficial subtypes [irrespective of health of patient], or those less than 1 cm size in immunocompromised patients or nodular subtypes).
Area H: “Mask areas” of face (central face, eyelids [including inner/outer canthi], eyebrows, nose, lips [cutaneous/mucosal/vermilion], chin, ear and periauricular skin /sulci, temple), genitalia (including perineal and perianal), hands, feet, nail units, ankles, and nipples/areola.
Area M: Cheeks, forehead, scalp, neck, jawline, and pretibial surface.
Area L: Trunk and extremities (excluding pretibial surface, hands, feet, nail units and ankles).
In this clinical case, the patient has a basal cell carcinoma that has a favorable pathology (i.e. superficial subtype) in the L zone, not an indication for Mohs micrographic surgery, irrespective of tumor size. Additionally, with a 1-cm tumor of this pathology subtype, her immunocompromised state is not an indication for Mohs micrographic surgery, either. The radiation was remote from the area she developed her basal cell carcinoma, so it is not an indication, either.
2018
A 60-year-old man presents with a 6-mm lesion of the forehead. The patient states that it has enlarged over a period of 2 years. Examination of a biopsy specimen shows squamous cell carcinoma (adenoid subtype) with a 1.5-mm depth of involvement. Which of the following is the most likely risk factor for recurrence of this patient’s lesion after surgical excision?
A) Anatomic location
B) Depth of involvement
C) Growth rate
D) Histologic subtype
E) Size
The correct response is Option D.
A number of risk factors for recurrence have been identified for squamous cell carcinomas.
Histologic subtype is one such factor. Adenoid, adenosquamous, and desmoplastic subtypes are considered high risk for recurrence.
Anatomic location is another such factor and is typically considered in combination with the size of the lesion. High-risk areas include the “mask” areas of the face (eyelids, eyebrows, periorbital, nose, lips, chin, temple, ear), as well as genitalia, hands, and feet. Lesions greater than 6 mm in these areas indicate a high risk for recurrence. Mid-risk areas include the cheeks, forehead, scalp, and neck, with lesions greater than 10 mm indicating a high risk for recurrence. Low-risk areas include the trunk and extremities, with lesions greater than 20 mm indicating a high risk for recurrence. Based on this, this patient with a 6-mm forehead lesion would not be considered at high risk for recurrence.
Rapid growth is a risk factor for recurrence. However, this patient’s lesion grew gradually over a period of 2 years and not rapidly.
Depth of involvement greater than 2 mm indicates a high risk for recurrence.
Other risk factors for recurrence include poorly defined borders, immunosuppression, prior irradiation, site of inflammatory process, neurologic symptoms, moderate/poor differentiation, and perineural/vascular involvement.
2018
Which of the following is the most appropriate surgical treatment recommendation for a 4-cm round sebaceous nevus of the scalp in a child?
A) Excision, skin grafting, and delayed tissue expansion
B) Serial excision without tissue expansion
C) Serial monitoring and selective excision
D) Tissue expansion and excision
E) Tissue expansion, excision, and rotational flaps
The correct response is Option C.
Historically, there has been a 10 to 15% reported malignant degeneration in nevus sebaceous in children and the recommendation had been for all lesions to be removed before puberty. More recent studies have shown malignant transformation of these lesions to be less than 1%. Therefore, the decrease in malignant change prompted a more conservative approach to nevus sebaceous based on serial monitoring and excision of lesions that are a source of irritation, difficult to monitor clinically, or aesthetically displeasing. Tissue expansion is an option in patients with giant nevus sebaceous and usually requires one to two rounds of expansion and serial excisions. However, this is not a first line treatment for a small 4-cm lesion. Although serial excision is an alternative reconstructive option, it is recommended only for larger lesions that can be excised in three stages or less. If that is not possible, then tissue expansion is the preferred procedure. Reconstruction with rotational flaps should be planned in consideration of natural facial aesthetic units and an effort should be made to maintain natural brow and hairline position and symmetry and avoid creating tension in the perioral, periorbital, and periauricular regions.
2018
Which of the following peripheral nerve tumors is most commonly associated with von Recklinghausen disease?
A) Astrocytoma
B) Glioblastoma
C) Neurilemoma
D) Neurofibroma
E) Schwannoma
The correct response is Option D.
A neurofibroma is a lesion of the peripheral nervous system, which is derived from Schwann cells, other perineural cell lines, and fibroblasts. Neurofibromas may arise sporadically, or in association with von Recklinghausen disease (neurofibromatosis 1 or NF1). A neurofibroma may arise at any point along a peripheral nerve, and comes in two varieties.
The plexiform neurofibromas are larger tumors that develop inside the body and tend to intimately involve the nerves, blood vessels, and other structures in the body. They can reside deep inside the body or closer to the skin. Plexiform neurofibromas can cause pain, numbness, weakness, and disfigurement. These tumors do have a small chance of becoming cancerous. Plexiform neurofibromas may also be asymptomatic.
Dermal (subcutaneous) neurofibromas are small, nodule-like tumors that grow on or just under the surface of the skin. They can be painful, itchy, disfiguring, or tender when touched, but they have no known potential to become cancerous. Dermal neurofibromas may also be asymptomatic.
Schwannomas are peripheral nerve sheath tumors that can be seen with NF1, but are more commonly associated with neurofibromatosis 2. The major distinction between a schwannoma and a solitary neurofibroma is that a schwannoma can be resected while sparing the underlying nerve, whereas resection of a neurofibroma requires the sacrifice of the underlying nerve. A neurilemoma is another name for a schwannoma.
Astrocytomas and glioblastomas are tumors of the central nervous system. Astrocytomas and optic gliomas can be seen in association with NF1.
2018
A 13-year-old girl is brought for evaluation because of a 4-month history of severe pain of the tip of the right index finger. There is no history of trauma. On examination, the finger appears normal with no visible swelling or discoloration. The pain is exacerbated by local pressure when the patient writes and during her weekly swimming lessons. MRI (T2-weighted) image is shown. Which of the following is the most likely diagnosis?
A) Digital fibroma
B) Giant cell tumor
C) Glomus tumor
D) Neuroma
E) Venous malformation
The correct response is Option C.
This lesion is a glomus tumor. Glomus tumors are benign hamartomas originating from the glomus body, a structure comprised of vascular and neural elements that is responsible for thermoregulation in the skin. These often inconspicuous tumors present with pain, point tenderness, and sensitivity to cold. X-ray studies may show cortical erosion of the bone adjacent to the lesion, and ultrasonography can provide confirmation. MRI is the most accurate imaging modality and the tumor appears as a bright, discrete mass on T2-weighted images.
Digital fibroma is a cutaneous fibroblastic proliferation and would be visible. It rarely causes pain and would not enhance on T2-weighted MRI imaging. Neuroma can cause focal pain as described in the vignette, but the enhancing focal lesion on the T2-weighted MRI effectively rules out solid masses such as neuroma or giant cell tumor (which is common but rarely causes pain or cold intolerance). Venous malformation would enhance on T2-weighted MRI, but would typically present with swelling and would not be as well circumscribed as the lesion shown here.
2018
A 72-year-old man comes to the office for evaluation of a 2-cm growth over the lower half of his nose that has been growing slowly during the past 15 years. A photograph is shown. Medical history includes acne rosacea. Physical examination shows a broad, exophytic mass. Which of the following is the most appropriate management?
A) Application of 5-fluorouracil
B) Direct excision and coverage with a forehead flap
C) Direct excision and coverage with a skin graft
D) Direct excision and healing by secondary intention
E) Observation only
The correct response is Option D.
Rhinophyma occurs on the far end of progressive acne rosacea involving the sebaceous glandular overgrowth of the skin. It most commonly occurs on the nose but phymas can occur elsewhere on the face.
In early stages, rhinophyma can be treated with isoretinoin and antibiotics; however, in advanced states it needs to be resected. Ablation modalities include dermabrasion, carbon dioxide laser excision, scalpel excision, or a combination of techniques. Since the procedure resects the skin to mid-dermis, skin grafting or other coverage is unnecessary and can lead to unsatisfactory aesthetic results. The best option is excision with secondary epithelialization.
2018
An 85-year-old man who takes an anticoagulant medication comes to the office for evaluation of a recurrent 1-cm nodular basal cell carcinoma at his nasal tip that has started to bleed intermittently. Medical history includes placement of a cardiac stent 1 month ago, after myocardial infarction. Which of the following is the most appropriate treatment for this patient?
A) Electrodessication
B) Excision with forehead flap
C) Pembrolizumab therapy
D) Superficial radiation therapy
E) Topical application of 5-fluorouracil
The correct response is Option D.
With a 5-year recurrence rate of about 3% for nodular basal cell carcinomas (BCC), superficial radiation therapy has become a viable alternative to Mohs micrographic surgery, which remains the gold standard for treatment of nonmelanomatous skin cancers.
Electrodessication has a high recurrence rate and would subject this anti-coagulated patient to the risk of bleeding after surgery or thrombosis should his anticoagulation be discontinued.
Excision with forehead flap would not be safe for a patient with a recent myocardial infarction.
Topical 5-fluorouracil is not indicated in the management of nodular BCC.
Pembrolizumab therapy is indicated for Stage IV melanoma.
2018
A 34-year-old woman comes to the office because of a 6 × 7-cm subcutaneous mass below the left scapula. Biopsy confirms dermatofibrosarcoma protuberans. To minimize recurrence yet maximize the chances of primary closure, which of the following is the most appropriate margin when planning wide local excision?
A) 5 mm
B) 10 mm
C) 20 mm
D) 40 mm
E) 50 mm
The correct response is Option C.
Several recent studies have confirmed that a surgical margin of 15 to 20 mm is associated with high rates of recurrence-free survival and primary closure when wide local excision is performed. Marginal excision is associated with higher rates of recurrence, and larger wide local excisions (>20 mm) are associated with similar recurrence-free survival but a much higher need for reconstructive surgery. Mohs micrographic surgery has shown promise, with higher initial clearance rates using smaller margins, but the question specifically addressed surgical margins when planning wide local excision.
2017
A 12-year-old girl develops a 12-mm nodule on her right cheek that grows slowly over 2 months. It is firm to the touch, mildly tender, and slightly bluish. There is no redness, ulceration, or visible punctum. Which of the following is the most likely diagnosis?
A) Hemangioma
B) Keratinous cyst
C) Pilomatricoma
D) Sebaceous nevus
E) Spitz nevus
The correct response is Option C.
Pilomatricoma (also known as pilomatrixoma or calcifying epithelioma of Malherbe) is a common, benign calcifying tumor of the hair appendages that mostly occur under the age of 20. Most occur in the head and neck, but the extremities and trunk are also affected. Surgical excision is the treatment of choice. Malignancy is very rare. Intraoperative findings show a calcific, friable mass adherent to the undersurface of the skin. Unlike a keratinous or sebaceous cyst, there is no discrete capsule or punctum (plugged pore). Recurrence is reported in the 1 to 2% range. This benign growth is related to a somatic (non-inherited) gene mutation CTNNB-1, that is involved in cell replication of the hair matrix.
Sebaceous nevus presents as a waxy textured skin patch, often present at birth. The scalp is a common site, although it may present elsewhere. Lesions are slow-growing and benign, but over the course of one’s lifetime, they have up to a 50% transformation rate to basal cell carcinoma, with squamous cell carcinoma less likely.
Hemangiomas are cutaneous blood vessel proliferations that are bright red or purple in color and are typically present at birth. While they are also common in childhood, they are more superficial in location and have a very different appearance versus pilomatricomas, which are subepithelial.
Spitz nevi are melanocytic lesions that can occur in children and adults. They can mimic melanoma though they are benign spindle cell lesions. Malignant transformation is not common, though atypical variants exist, therefore excision is recommended. They appear as dark brown or black macules on the skin.
2017
A 58-year-old Caucasian farmer comes to the office because of several pink scaly macules on his cheeks and nose. Biopsy of one of the lesions shows pleomorphic keratinocytes within the basal layer of the epidermis and hyperkeratosis, consistent with actinic keratosis. If left untreated, which of the following is the likelihood that these lesions will become malignant?
A) 0%
B) 10%
C) 30%
D) 50%
E) 70%
The correct response is Option B.
The patient has actinic keratoses (AKs). AKs are common in in people with significant sun exposure and are a response to ultraviolet radiation. The likelihood of malignant transformation to squamous cell carcinoma (SCC) is approximately 10%.
There are various treatment modalities for AKs, including cryotherapy, 5-flurouracil (5-FU), photodynamic therapy, superficial glycolic peels, and imiquimod. Cryotherapy with liquid nitrogen is commonly used for isolated lesions, while the other therapies are more commonly used for diffuse disease.
2017
A 7-year-old boy is evaluated because of new nodular lesions on his skin. Patient history includes a jaw cyst, pits in the hands and feet, and a treated meduloblastoma. Biopsy is planned. Which of the following is the most likely diagnosis?
A) Basal cell carcinoma
B) Melanoma
C) Merkel cell carcinoma
D) Sebaceous adenocarcinoma
E) Squamous cell carcinoma
The correct response is Option A.
The patient has basal cell nevus (Gorlin) syndrome. It is an autosomal dominant genetic condition affecting 1 in 56,000. Males and females are equally affected. It is caused by a mutation in the PTCH1 gene. Clinical characteristics include multiple basal cell carcinomas, odontogenic cysts of the mandible, facial dysmorphism, and skeletal abnormalities of the vertebrae, skull, and ribs. 5 to 10% of patients will develop medulloblastoma. The other malignancies are not associated with Gorlin syndrome.
2017
A 50-year-old woman with a history of scleroderma is evaluated because of a 1.5-cm lesion on her right cheek. Patient history includes basal cell carcinoma excision at the same site 3 years ago. A punch biopsy shows basal cell carcinoma (micronodular subtype). Which of the following is the most appropriate indication for Mohs micrographic surgery in this patient?
A) Histologic subtype
B) History of scleroderma
C) Location of lesion
D) Recurrence of lesion
E) Size of lesion
The correct response is Option D.
Mohs micrographic surgery is a surgical technique in which tumor excision and microscopic examination of tissue margins are performed by the same surgeon. Use of a beveled excision and careful mapping of the peripheral and deep margins of horizontal frozen sections allow for comprehensive examination of all the borders of the excised tissue, resulting in excellent cure rates. In addition to the high cure rate, Mohs surgery is a tissue-sparing procedure that is an important advantage in cosmetically and functionally sensitive areas and contrasts with traditional approaches in which a set margin of excision is performed.
Indications for Mohs surgery include recurrent basal cell carcinomas (BCC) and squamous cell carcinomas (SCC), locations prone to recurrence (“H-zone” of the face: inner canthus, nasolabial fold, nose, periorbital, temple, upper lip and periauricular regions, retroauricular, and chin), at/near critical structures (e.g., eye, lip), large tumors (>2 cm), ill-defined tumor margins, aggressive histology (BCC - morpheaform infiltrative, basosquamous, perineural; SCC - poorly differentiated, invasive, perineural), and special hosts (immunosuppressed, basal cell nevus syndrome, xeroderma pigmentosum). Therefore, in this patient, the primary indication for Mohs surgery would be the recurrent nature of her BCC.
2017
A 25-year-old obese man is evaluated because of new onset of inflamed nodules involving the bilateral axillae. A diagnosis of hidradenitis suppurativa is made. Which of the following is the most appropriate initial medication for treatment of this patient’s condition?
A) Botulinum toxin type A
B) Clindamycin
C) Cyclosporine
D) Etanercept
E) Prednisone
The correct response is Option B.
Hidradenitis suppurativa is a chronic inflammatory skin disease. Also known as acne inversa, it is characterized by recurrent nodules and abscesses, typically of apocrine gland–bearing skin.
This patient has mild hidradenitis, with an initial presentation of a few abscesses without sinus tracts or cicatrization/scarring.
Clindamycin applied topically is often used as a first-line therapy for mild hidradenitis. In a randomized, placebo-controlled trial, patients treated with twice-daily topical application of 1% clindamycin solution were found to have significantly less disease burden, and the treatment was well tolerated with few side effects.
Although there have been reports of the use of botulinum toxin in the treatment of hidradenitis, its role and efficacy in this setting are currently unclear.
Etanercept is a TNF-alpha inhibitor. Although some TNF-alpha inhibitors, particularly infliximab, have shown efficacy in patients with moderate-to-severe hidradenitis, data are conflicting with regard to Etanercept.
Prednisone is occasionally used to calm the inflammatory process in severe hidradenitis. However, it does not prevent formation of new lesions and is rarely used for long-term therapy in patients with hidradenitis because of possible adverse effects.
A few case reports have described improvement with cyclosporine in refractory cases of hidradenitis. However, it is typically not used for initial medical treatment of hidradenitis, and duration of use is often limited by adverse effects.
2017
A 75-year-old woman is evaluated because of a new skin lesion on the right upper eyelid. Examination of the specimen obtained on biopsy shows a 1-cm Merkel cell carcinoma. In addition to regional node sampling, which of the following is the most appropriate excision and adjuvant management in this patient?
A) 1-cm margins and chemotherapy
B) 2-cm margins and chemotherapy
C) 1-cm margins and postoperative radiation therapy
D) 2-cm margins and postoperative radiation therapy
E) 5-mm margins and postoperative radiation therapy
The correct response is Option C.
Merkel cell carcinoma, an aggressive neuroendocrine tumor, is most likely. It presents in older, immunocompromised women in sun-exposed areas. About 80% of Merkel cell carcinomas are secondary to polyomavirus infection. Treatment of the primary tumor should be wide local excision or Mohs micrographic surgery. For wide local excision of tumors smaller than 2 cm, the recommended surgical margin should be 1 cm. As there is a high rate of occult nodal metastasis, and nodal status is associated with mortality rates, biopsy of the sentinel node is recommended for all cases regardless of primary tumor size. Merkel cell carcinoma is a radiosensitive tumor, and postoperative adjuvant radiation therapy has been shown to decrease local recurrence. Chemotherapy is only currently indicated for palliation and distant metastasis.
2017
A 62-year-old man is evaluated because of a new skin lesion in his back. Excision of the lesion with administration of a local anesthetic agent is planned. Medical history shows hypertension and coronary artery disease treated with coronary balloon angioplasty 10 years ago. He takes 81 mg of aspirin daily. Preoperatively, which of the following is the most appropriate aspirin regimen for this patient?
A) Maintaining current dosage
B) Withholding for 1 day
C) Withholding for 2 days
D) Withholding for 7 days
E) Withholding for 14 days
The correct response is Option A.
For this patient with increased risk of cardiovascular events, the safest approach is not to withhold aspirin prior to dermatologic surgery.
Aspirin inhibits platelet aggregation by irreversibly binding to the cell’s cyclooxygenase enzyme stores, blocking the production of thromboxane. Its use at lower doses in long-term primary and secondary prevention of cerebrovascular and cardiovascular thrombotic events is well established.
Withholding of daily aspirin in patients with known cardiovascular disease can lead to a platelet rebound phenomenon featuring increased thromboxane production, decreased fibrinolysis, and a prothrombotic state. Discontinuation of oral antiaggregants has been found to be an independent predictor of both death and major ischemic events.
Several studies revealed no significant increase in the risk of bleeding complications after cutaneous surgery in patients who continued taking aspirin perioperatively.
2017
A 20-year-old man comes to the office for definitive treatment of a punch biopsy–proven dermatofibrosarcoma protuberans (DFSP) of the scalp. Which of the following is the most appropriate treatment plan?
A) Cryoablation
B) Radiation
C) Referral for Mohs micrographic surgery
D) Resection with 0.5-cm margin
E) Resection with 1-cm margin
The correct response is Option C.
Dermatofibrosarcoma protuberans (DFSP) is relatively uncommon, soft-tissue-only tumor that is locally aggressive. Since it can extend along connective tissues along the deep layers, margins required for DFSP need to be no less than 2 cm for an acceptable non-recurrence rate, and even then it is quite high. Predicted rate of recurrence is anywhere from 11 to 20% with a 3-cm margin.
Mohs micrographic surgery has demonstrated to have a much lower recurrence rate, with multiple studies demonstrating less than 10%. Subsequently, Mohs micrographic surgery is the best initial treatment plan for complete resection of DFSP.
Radiation therapy is contraindicated for DFSP. Cryoablation is employed for precancerous skin lesions.
2017
Which of the following patients’ skin lesions is most suggestive of malignancy on the basis of its clinical features?
A) A 14-year-old boy with a 5-mm, round, brown macule present since birth on the distal aspect of the thigh
B) A 22-year-old woman with a 6-mm friable, pedunculated papule present for 6 weeks on the cheek
C) A 55-year-old man with a 5-mm pink, pearly papule present for 6 months on the lateral nasal sidewall
D) A 70-year-old man with a 1.5-cm waxy, yellow and brown, scaly plaque present for several years on the left temple
The correct response is Option C.
Once an individual’s personal and family histories are considered, the history and appearance of a suspicious skin lesion will provide important information and provide clues about a diagnosis.
The “ABCD” (Asymmetry, Border irregularity, Color variegation, Diameter >6 mm) criteria are important for assessing potential malignancy of pigmented lesions. A flat, unchanging pigmented lesion in a young patient is unlikely to be malignant.
A pyogenic granuloma classically presents after local trauma and is characterized by a friable papule that bleeds easily.
Basal cell carcinoma and squamous cell carcinoma are the most common cutaneous skin malignancies. They may present as discrete, slowly growing lesions that have a history of bleeding and ulceration. Basal cell malignancies have a characteristic appearance of round, oval nodules with a shiny, pearly appearance and overlying telangiectasias.
Seborrheic keratoses are common benign skin lesions found in old age. They are a proliferation of immature keratinocytes and have a characteristic appearance of being well circumscribed, scaly, and have a “stuck on” appearance. While unsightly, these lesions have no malignant potential.
2017
A 62-year-old woman with biopsy-proven basal cell carcinoma of left mid cheek presents for consultation for surgical treatment. On physical examination, the lesion is 0.6 cm in diameter and has indistinct borders. Which of the following criteria is the most likely indication for Mohs micrographic surgery in this patient?
A) Anatomical location of the cancer
B) Diagnosis of basal cell carcinoma
C) Indistinct borders
D) Patient age
E) Size of the carcinoma
The correct response is Option C.
In the case presented above, the strongest indication for Mohs micrographic surgery comes from the anatomic finding of indistinct borders. Other findings are not necessarily indications for Mohs. Other proven indications are recurrent cancer, high risk zones of the face, morpheaform basal cell cancer, or evidence of neurovascular involvement. By some studies, larger sized basal cell cancers (>2 cm) may be indications.
By definition, Mohs micrographic surgery is a technique for treatment of complex or ill-defined skin cancers with examination of 100% of tissue. One physician performs the procedure, acting in two distinct capacities: surgeon (excising the cancer) and pathologist (reading the slides). Usually, the final pathologic clearance is given on the same day as the resection. This is in comparison with a wide local excision technique, which is performed by two different physicians: a surgeon who removes the cancer and a pathologist who reads it separately. In the latter scenario, although a “wet” read can be done on the same day, the final pathologic evaluation has to await the permanent preparation of slides and a final read. Also, using the routine pathologic evaluation, only 2% of the margins are looked at (using the common “bread loafing” technique), compared with the 100% of tissues evaluated using the Mohs technique.
The vast majority of Mohs resections is done with one or two excisions. Although at times there is a need for multiple excisions, the need for excisions is driven by the positive margins detected pathologically. In Mohs technique, the amount of healthy tissue taken to obtain “clear” margins is the minimum needed to do so, thus preserving the healthy tissue, which can be critically useful in the ensuing reconstruction. These margins are definitively assessed on that same day of surgery, so once the patient leaves the Mohs surgeon’s office, he or she knows the cancer has been completely removed. This is why the margin control is superior in Mohs technique compared with other surgical techniques.
2016
A 75-year-old man comes to the office because of a 5-year history of a pruritic lesion on the right groin that has been enlarging gradually in size. A photograph is shown. Examination of a specimen obtained on biopsy shows Paget disease. Which of the following is the most appropriate next step in management?
A) Oral miltefosine
B) Topical hydrocortisone
C) Topical miconazole
D) Wide excision
E) Observation
The correct response is Option D.
This patient described has extramammary Paget disease and the treatment is wide excision. Paget disease of the breast also presents with eczematous skin changes and is associated with breast cancer. Extramammary Paget disease, however, is an intraepithelial carcinoma that commonly involves the vulvar, perianal, perineal, scrotal, and penile regions. It presents as well-defined, moist, erythematous plaques associated with pruritis. Histopathologic examination shows epidermal acanthosis and elongated rete ridges. Paget cells are large intraepidermal cells with a large nucleus and abundant pale cytoplasm. There is a 7 to 40% rate of associated malignancy. Wide excision is the standard of care, and recent reports have shown that Mohs micrographic surgery can improve evaluation of resection margins.
Observation is not appropriate for extramammary Paget disease given the potential risk for malignancy. Topical treatment with steroids or antifungals is also not appropriate. Oral miltefosine is a treatment for leishmaniasis, an infectious disease that can involve the skin, mucous membranes, and internal organs. Although cutaneous leishmaniasis can present with ulcerating lesions or a dense dermal infiltrate, the histology is predominantly histiocytes, lymphocytes, and plasma cells.
2016
An otherwise healthy 65-year-old man comes to the clinic because of a 3-cm ulcerated lesion of the scalp. There are no palpable regional lymph nodes. Chest x-ray study shows no abnormalities. A punch biopsy is performed and a diagnosis of well-differentiated squamous cell carcinoma is made. Wide local excision of the lesion is planned. Which of the following is the recommended minimum surgical margin in this patient?
A) 1 mm
B) 2 mm
C) 4 mm
D) 6 mm
E) 12 mm
The correct response is Option D.
The most appropriate surgical margin recommended for the clinical scenario described is 6 to 10 mm.
Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer after basal cell carcinomas. They are broadly categorized into low- and high-risk lesions depending on size, location, depth of invasion, recurrence, and patient factors such as immunosuppression. A 4-mm margin of healthy tissue is recommended for lower-risk lesions. This category includes well-differentiated tumors smaller than 2 cm in diameter that do not occur on the scalp, ears, eyelids, lips, or nose, and do not involve subcutaneous fat. Therefore, simple excision is most valuable in the treatment of small primary squamous cell carcinomas on the trunk, extremities, or neck, where tissue sparing is less essential. The recurrence rate after the excision of low-risk lesions ranges from 5 to 8%.
A 6-mm margin of healthy tissue is recommended for lesions that are larger than 2 cm, invasive to fat, or in high-risk locations (i.e., central face, ears, scalp, genitalia, hands, feet). Given the cosmetic and functional impact of these wider margins, tumors in this latter category are often removed via Mohs micrographic surgery to achieve high cure rates while sparing healthy tissue. The depth of an excision should always include a portion of the subcutaneous fat.
Cure rates following simple excision of well-defined T1 lesions may be as high as 95 to 99%. The generally accepted 5-year cure rate for primary tumors treated with standard excision is 92%; this rate drops to 77% for recurrent cSCC. No large randomized studies have addressed the issue of appropriate margin size in cSCC, as has been done for melanoma. The recommendations for margin size should be taken only as rough guidelines, with the understanding that large, aggressive lesions frequently have substantial extension beyond the apparent superficial boundary. Therefore, a surgeon’s experience and judgment when planning surgical margins is paramount to the successful treatment of cSCC.
2015
A 24-year-old woman is evaluated because of a slow-growing subcutaneous mass of the scalp. An excisional biopsy is performed, and pathologic examination shows keratin and its breakdown products. Which of the following is the most likely origin of this lesion?
A) Adipocyte
B) Capillary
C) Hair follicle
D) Mechanoreceptor
E) Sebaceous gland
The correct response is Option C.
Pilar cysts, also known as trichilemmal cysts, originate from the outer root sheath of the hair shaft. They present as firm, slow-growing subcutaneous nodules, and may be difficult to differentiate clinically from epidermoid cysts. They are commonly found on the scalp where they are the most common cutaneous cyst. They are lined by stratified squamous epithelium, which undergoes keratinization. In some cases, these lesions can demonstrate aggressive biologic behavior (proliferating trichilemmal tumors, malignant proliferating trichilemmal tumors), in which case they should be completely excised.
Lesions that originate from adipocytes include lipomas and angiolipomas.
Lesions of vascular origin include cherry angiomas and pyogenic granulomas.
2015
A 45-year-old woman is evaluated because of a 1-year history of skin abnormalities. Physical examination shows areas of thickened skin involving the forearms and hands. Telangiectasias are seen on the face and oral cavity. A review of systems discloses symptoms of heartburn and dysphagia. Which of the following is the most likely diagnosis?
A) Amyloidosis
B) Dermatomyositis
C) Hypothyroidism
D) Scleroderma
E) Systemic lupus erythematosus
The correct response is Option D.
The scleroderma spectrum of disorders includes localized scleroderma and systemic sclerosis, both of which are characterized by thickened sclerotic skin. Localized scleroderma involves only the skin, whereas systemic sclerosis is associated with extracutaneous involvement and is subcategorized into limited and diffuse forms. Limited cutaneous systemic sclerosis is restricted to the hands, distal forearm, face, and neck. Limited scleroderma is sometimes referred to as CREST syndrome, which is an acronym for the following features: calcinosis, Raynaud syndrome, esophageal dysmotility, sclerodactyly, and telangiectasia. Diffuse cutaneous systemic sclerosis includes truncal involvement (chest, abdomen, upper arms, shoulders).
In most patients with systemic sclerosis, there is gastrointestinal involvement. Symptoms are present in more than half of patients and most commonly are related to gastroesophageal reflux disease, resulting in symptoms such as heartburn and dysphagia. Other findings in systemic sclerosis include: diarrhea, mucocutaneous telangiectasia of the face/lips/oral cavity/hands, dyspnea on exertion/interstitial pulmonary disease, and digital infarctions/pitting.
Amyloid infiltration of the skin may produce thickening and stiffness. Telangiectasias are not a feature of amyloidosis. Gastrointestinal involvement with amyloid typically does not cause esophageal reflux or heartburn.
Dermatomyositis is an idiopathic inflammatory myopathy characterized by skin and muscle abnormalities. Cutaneous involvement manifests in the form of distinct rashes, such as of the upper eyelids (heliotrope rash), hands (Gottron sign), and chest and shoulders (shawl sign). However, thickened skin of the trunk and limbs, and telangiectasias are not features of dermatomyositis.
Hypothyroidism can result in cutaneous and dermal edema (myxedema). Other findings include fatigue, cold intolerance, weight gain, constipation, dry skin, myalgia, and menstrual irregularities. It is not associated with telangiectasias.
Systemic lupus erythematosus (SLE) is a chronic inflammatory disease that can affect the skin, joints, kidneys, lungs, nervous system, serous membranes, and/or other organs of the body. Mucocutaneous changes include butterfly rash, erythematous plaques (discoid lesions), and ulcers. SLE is not associated with telangiectasias.
2015
A 55-year-old woman comes to the office because of a 3-year history of a raised, dark brown lesion on her back. The lesion is not painful and does not bleed. A photograph is shown. An excisional biopsy is performed. Pathologic examination shows proliferation of cells from the basal layer of the epidermis with cystic inclusions. The lesion exhibits hyperkeratosis, acanthosis, and papillomatosis. Which of the following is the most likely diagnosis?
A) Basal cell carcinoma
B) Malignant melanoma
C) Nevus sebaceous
D) Seborrheic keratosis
E) Verrucous carcinoma
The correct response is Option D.
The lesion is a seborrheic keratosis, also known as verruca senilis or pigmented papilloma. Seborrheic keratoses are common benign lesions that may begin to appear during the fifth decade of life. They arise from the basal layer of the epidermis and are composed of well-differentiated basal cells. They often contain cystic “inclusions” of keratinous material called “horn cysts.” Lesions exhibit hyperkeratosis (thickening of the stratum corneum), acanthosis (diffuse epidermal hyperplasia and thickening of the skin), and papillomatosis (skin surface elevation). The growth and depth of pigmentation vary directly with exposure to sunlight. If left untreated, they will enlarge gradually and increase in thickness. Seborrheic keratoses typically do not involute spontaneously. They may appear on the head, neck, and trunk after age 50 years and are often distinctly marked and have a waxy, stuck-on appearance. The surface is soft and oily to the touch. Sizes can range from 1 mm to 5 cm. No treatment is necessary, but these lesions are cosmetically unappealing, and for that reason alone, patients may request to have them removed. It is extremely rare for cutaneous malignancies to develop within seborrheic keratoses.
A verrucous carcinoma is a variant of squamous cell carcinoma. As such, it requires wide local excision with negative margins for treatment.
Nevus sebaceous (Jadassohn nevus) may be described as cerebriform, nodular, or verrucous. It is hairless and can appear on the scalp, face, or neck. When present at birth, it persists throughout life and tends to become more verrucous and nodular during the growth phase associated with puberty. Over time, these lesions are associated with a risk of basal cell carcinoma, which occurs in approximately 15 to 20%. Keratoacanthoma and squamous cell carcinoma may also develop, although with much less frequency than basal cell carcinoma. Because of the risk of malignant transformation, complete excision is generally recommended.
Melanoma results from malignant transformation of the melanocyte; the pigment-producing cell of the body can occur anywhere melanocytes are present, including skin, eye, and the mucous membranes of the upper digestive tract, sinuses, anus, and vagina. The incidence of cutaneous melanoma in the United States has increased steadily over the past 50 years and is now 15 per 100,000. Worldwide, the incidence of melanoma is generally reflective of variation in genetic, phenotypic, and ultraviolet (UV) exposure risk factors. Major risk factors include exposure to UV radiation and genetic predisposition. The exposure risk primarily involves intermittent, damaging exposure to the sun such that history of a severe sunburn (blistering or pain for more than 2 days), even in youth, confers an approximately twofold increase in risk. Patients who have fair skin, blue eyes, red hair, and are prone to freckling are at increased risk for melanoma. Mutations in two genes are associated with hereditary melanoma predisposition.
2015
A 60-year-old woman comes to the office for evaluation of a firm, violaceous, 3-cm lesion of the left cheek. An incisional biopsy shows a Merkel cell tumor. The residual margins are positive. Which of the following is the most appropriate management?
A) Chemotherapy
B) Laser ablation
C) Mohs micrographic surgery
D) Radiation therapy and chemotherapy
E) Wide local excision and radiation therapy
The correct response is Option E.
Merkel cell tumor is an unusual and highly aggressive skin cancer. More than 50% of Merkel cell tumors occur in the head and neck region. Risk factors for Merkel cell tumors are exposure to sun and ultraviolet light, and immunosuppression. There is a recent association with Merkel cell polyomavirus.
Merkel cell generally presents as a firm, painless nodule (up to 2 cm in diameter) or as a mass (>2 cm in diameter). Although classically described as red in color, it may be flesh-colored or blue. It often enlarges rapidly.
The standard of management is surgical excision combined with radiation therapy. Radiation therapy decreases local recurrence rates. Node-negative patients with no distant metastasis treated with surgery and radiation have 5-year survival rates of approximately 90%. Mohs micrographic surgery and wide local excision are both accepted modalities of surgical resection. It is well known that surgery alone is insufficient to cure or control Merkel cell tumors. Consideration should be given to evaluation of the lymph nodes. Sentinel node biopsy is a common modality.
2015
A 14-year-old girl with Fitzpatrick Type V skin comes to the office for evaluation of a nevus on the right side of the face. Physical examination shows a macular, bluish grey, irregular area of hyperpigmentation involving the right infrapalpebral region, nasolabial fold, and zygomatic region. Pigmentation of the right sclera is noted. Which of the following is the most appropriate treatment for this lesion?
A) Camouflage therapy
B) Cryotherapy
C) Dermabrasion
D) Mohs micrographic excision
E) Q-switched ruby laser
The correct response is Option E.
This patient has the acquired form of nevus of Ota, also known as nevus fuscoceruleus ophthalmomaxillaris or oculodermal melanocytosis, a dermal melanocytic hamartoma that demonstrates bluish hyperpigmentation along the ophthalmic and maxillary divisions of the trigeminal nerve. The failure of complete embryonic migration of melanocytes from the neural crest to the epidermis results in dermal nesting with the resultant dermal melanin causing the Tyndall effect. This disorder primarily affects darker-pigmented individuals and is more prevalent in females. It has a bimodal age incidence, with a peak at 1 year of age and a second around puberty. The lesion tends to become increasingly prominent with age, puberty, and postmenopausal state. Most patients have no family history. Ophthalmologic examination is recommended because of a reported 10% association with ipsilateral glaucoma. Malignant degeneration to melanoma occurs in approximately 4% of reported cases and is more frequent in lighter-skinned individuals. Diagnosis is mainly clinical with confirmatory biopsy indicated when the diagnosis is uncertain or in rapidly expanding or nodular lesions suggestive of malignancy.
The most effective treatment option is laser therapy, particularly with a Q-switched laser with ruby (694 nm), alexandrite (755 nm), or neodymium: yttrium-aluminum-garnet (1064 nm). The wavelength, pulse duration, and energy densities inherent in the Q-switched laser provide the desired parameters for melanin photothermolysis. Dyspigmentation is a possible complication, although it is mostly transient.
Before the advent of laser therapy, treatment options were suboptimal. Makeup or camouflage therapy offered only temporary improvement. Dermabrasion followed by cryotherapy had the potential for dermal scarring and atrophy and was ineffective for those lesions with deep dermal melanocytes. Surgical excision options were also associated with scarring. Mohs micrographic excision has not been described for excision of these lesions.
2014
An 87-year-old Caucasian man comes to the office with multiple 5- to 6-mm lesions on the forehead. He has a long history of sun exposure. Physical examination shows the lesions are erythematous, rough, and scaly. Which of the following is the most appropriate treatment?
A) Dexamethasone
B) Docosanol
C) Imiquimod
D) Isotretinoin
E) Observation with 1-month follow up
The correct response is Option C.
This patient’s lesions are most consistent with actinic keratoses. Actinic keratoses are most commonly seen in fair-skinned individuals in areas that have had long-term sun exposure. They are the most common skin lesions to demonstrate malignant potential and may progress to squamous cell carcinoma.
Given the propensity of actinic keratoses to malignant transformation, treatment is generally recommended over observation. For multiple lesions, topical agents are generally effective and well tolerated. Imiquimod is thought to exert its effects by inducing a local immune response as well as apoptotic pathways. Other effective treatments include photodynamic therapy, cryotherapy, 5-fluorouracil, and diclofenac gel.
Dexamethasone is a corticosteroid typically used for inflammatory or autoimmune skin conditions. Isotretinoin is used to treat cystic acne. Docosanol is an antiviral medication used for herpes simplex.
2014
A 65-year-old man comes to the office with a 2-cm basal cell carcinoma involving the left nasal ala extending across the nasofacial junction onto the cheek. A photograph is shown. Medical history includes previous melanoma. Which of the following is an indication for Mohs micrographic surgery over conventional excision in this patient?
A) Cancer size
B) Diagnosis of basal cell carcinoma
C) History of previous melanoma
D) Location of the lesion
E) Patient age
The correct response is Option D.
Mohs micrographic surgical technique has demonstrated cure rates of 99% for primary basal cell carcinomas and up to 95% for recurrent basal cell carcinomas. In this particular patient, the strongest indication for use of the Mohs technique is the anatomical location. The nose is considered a high-risk location in the classically described “H-zone.” This patient underwent Mohs excision with multi-stage forehead flap reconstruction, as shown in the photographs. Patient age, history of previous melanoma, and tumor size 2 cm or less are not standard indications for Mohs excision. Other indications for Mohs technique include the following: Recurrent basal cell/squamous cell carcinomas, Locations prone to recurrence- “H-zone” of the face: periorbital, periauricular, temple, upper lip, nose/nasolabial fold, and chin, Tumors involving critical structures such as the eyelid or lip, Functionally important areas such as the genitals, perianal location, hands, and feet, Tumors arising in sites of previous irradiation therapy, Large tumors (> 2 cm) Lesions with ill-defined tumor margins, Histologic aggressive subtype (morpheaform, basosquamous, perineural, and invasive/poorly differentiated squamous cell carcinoma) Tumors arising in immunosuppressed patients such as transplant recipients or patients with genetic predisposition (basal cell nevus syndrome, xeroderma pigmentosum)
2019
A 53-year-old man presents with the lower eyelid skin lesions shown in the photograph. The lesions have been slowly growing over the past 12 months. Which of the following treatment options is the most appropriate?
A) Excision of the mass and overlying skin
B) Excision with 1-mm tissue margins
C) Excision with 2-mm tissue margins
D) Excision with 4-mm tissue margins and sentinel lymph node biopsy
E) Mohs micrographic surgery
The correct response is Option A.
The patient presents with xanthelasmata, which are localized accumulation of lipid deposits on the eyelids. Multiple treatment modalities are available, including chemical peels, cryotherapy, and laser ablation. Traditionally, surgical excision has been used and yields excellent cosmetic outcomes. As the lesions are benign, there is no indication for Mohs micrographic surgery and no margins are required.
2021
A 65-year-old man presents with the rapidly growing, painful dorsal hand lesion shown in the photographs. It is not fixed to the underlying structures and the tendon and bone are not involved. He is a kidney transplant recipient and has been on immunosuppression for the past 10 years. Eighteen months ago, he was treated for a previous squamous cell carcinoma on the contralateral hand. Which of the following are the most appropriate surgical margins and depth of excision for this lesion?
A) 1-cm peripheral margins, excision to the deep dermal level
B) 1-cm peripheral margins, excision to the deep subcutaneous level
C) 1-mm peripheral margins, excision to the deep dermal level
D) 1-mm peripheral margins, excision to the deep subcutaneous level
The correct response is Option B.
Squamous cell carcinoma that arises in immunocompromised patients tends to behave more aggressively than tumors in immunocompetent patients. Resection with at least 6-mm margins (some recommend up to 10-mm margins), extending into the subcutaneous tissue, is recommended. Cure rates with Mohs surgery and with frozen section margin control are similar to those for wide local excision.
One-mm surgical margins are too narrow for squamous cell carcinoma, and would lead to a high rate of reoperations for positive microscopic margins. Furthermore, the entire dermis must be completely excised, along with at least part of the subcutaneous tissue, as lesions like this are likely to penetrate to that depth.
2021
A 55-year-old man presents with a fungating mass of the right shoulder that has been enlarging for the past 12 years. A photograph is shown. Medical history is unremarkable. The patient reports that he spent his youth working outside. He has a history of smoking. Which of the following is the most significant risk factor for development of this lesion in this patient?
A) CDK4 mutation
B) Previous use of topical steroids
C) Smoking history
D) Sun exposure
The correct response is Option D.
The patient presents with a nodular ulcerated basal cell carcinoma to the right shoulder. Basal cell carcinoma is the most common malignancy in the United States due to the increase in sun exposure and tanning salons. The most common risk factor for basal cell carcinomas is sun exposure. Generally, they do not metastasize and are resectable, but do lead to large oncologic resections if left to progress, as is the case in the patient described. Smoking history, although important, does not have a major impact on the risk for basal cell cancer. Marjolin ulcers are a variant of squamous cell carcinoma that results from the chronic inflammatory process that follows burns and is not a risk factor for basal cell carcinoma. Immunosuppression is a risk factor for basal cell carcinomas, but it is not as great as sun exposure and this patient has no history of immunosuppression. Other risk factors for basal cell carcinoma include being male and of older age, but these are not listed as possible choices. A mutation in the CDK4 gene is linked to familial melanoma and would have no relation to the basal cell tumor in this patient. Topical steroid use has no known impact on risk for development of basal cell carcinoma.
2022
A 60-year-old woman presents with worsening painful ulceration of a prior healed surgical site of the left lower extremity after undergoing hidradenitis excisions 10 years ago. She reports no trauma and has had no fevers or chills. Examination shows some drainage at the wound site. She undergoes treatment with debridement, antibiotics, and multiple types of dressings without progress of wound healing. Photographs are shown. Which of the following is the most appropriate next step in management?
A) Debridement and biopsy
B) Debridement and dermal allografting
C) Debridement and negative pressure dressing
D) Excision and coverage with a flap
E) Excision and skin grafting
The correct response is Option A.
Marjolin ulcers are malignancies (most commonly aggressive squamous cell carcinoma) that arise from areas of chronic irritation, injury, or unstable scar. These malignancies frequently occur over many years. This malignant degeneration is most commonly associated with burns; however, it can be associated with a multitude of other types of nonhealing wounds such as traumatic wounds, osteomyelitis, pressure sores, any type of ulcer, laceration, venous stasis ulcer, or fistulas. The rate of incidence is approximately 2% in burn scars, with a predilection for the extremities, especially in the lower limbs. There is often a delay in diagnosis, since the appearance of a nonhealing ulcer with heaped-up edges mimics other types of ulcerations. Marjolin ulcer should be ruled out in a chronic nonhealing ulcer in the setting of a long-term scar/injury/burn.
Diagnosis of Marjolin ulcer is typically made by tissue biopsy with pathologic evaluation. Squamous cell carcinoma is the most common type of histology seen in Marjolin ulcer, although basal cell carcinoma, malignant fibrous histiocytoma, malignant melanoma, liposarcoma, fibrosarcoma, eccrine syringofibroadenoma, Merkel cell carcinoma, and keratoacanthoma have all been described. For patients with squamous cell carcinoma (most common type), the degree of differentiation is important prognostically. The risk for metastasis is highly correlated with the degree of differentiation and grade of the tumor. There is early lymph node metastasis in 30% of patients.
Treatment is surgical with wide local excision with pursuit of negative margins. Sentinel lymph node biopsy is frequently pursued. Deeper ulcers involving bone may warrant amputation of the involved extremity.
Marjolin ulcer must be diagnosed and treated (or the diagnosis excluded) before considering any other treatments.
2022
A 50-year-old woman presents with a 1.5-cm white plaque on the left cheek that has been slowly growing for the past 3 years. A photograph is shown. Examination of the specimen obtained on biopsy shows perineural invasion and basaloid epitheloid cells displaying ductal lumina. Which of the following is the most likely diagnosis?
A) Keratoacanthoma
B) Malignant melanoma
C) Microcystic adnexal carcinoma
D) Squamous cell carcinoma
The correct response is Option C.
Microcystic adnexal carcinoma (MAC) is a slow-growing skin cancer that primarily affects the head and neck and usually presents as a fleshy, plaque-like lesion. MAC is commonly misdiagnosed as basal or squamous cell carcinomas amongst others. MAC commonly has perineural invasion (PNI) and, as its names implies, affects apocrine structures. Although PNI can occur with basal cell carcinoma, squamous cell carcinoma, and melanoma, the latter two are generally much faster growing and this finding is still much less common. For basal cell carcinoma, PNI is typically observed in patients with advanced disease. Keratoacanthoma is a form of well-differentiated squamous cell carcinoma and is generally fast growing. Treatment of MAC is typically carried out with complete circumferential, peripheral, and deep margin assessment, and most often with Mohs micrographic surgery.
2022
A 17-year-old girl presents to the clinic to have the lesion in the photograph removed. She has had it since birth. She does not like its appearance and has noted it has changed in size and shape during the last two years. Histopathologic examination of the specimen is most likely to show which of the following?
A) Amelanotic melanoma
B) Basal cell carcinoma
C) Nevus sebaceous
D) Squamous cell carcinoma
E) Trichoblastoma
The correct response is Option C.
The photograph shows a sebaceous nevus of Jadassohn, and on pathology, a benign organoid nevus is the most likely finding. Given the patient’s age, malignant transformation is very rare (around 2.5%). Until recently, the most common transformation has been thought to be basal cell carcinoma (1.1%). However, it is now thought that many of these were trichoblastomas. A melanoma present since childhood does not fit the presentation of this patient.
2022
A 25-year-old woman comes to the office because of a slow-growing upper extremity mass. Physical examination also shows numerous smaller lesions and masses scattered over the patient’s body. She reports that her mother has similar lesions. MRI images are shown. Which of the following is the most likely diagnosis?
A) Glomus tumor
B) Hemangioma
C) Lymphatic malformation
D) Plexiform neurofibroma
E) Venous malformation
The correct response is Option D.
The patient is presenting with neurofibromatosis. The T2-weighted MRI image shows skin thickening and hypertrophy of the subcutaneous tissues consistent with a cutaneous plexiform neurofibroma. The T1-weighted MRI image shows a muscle split fat sign where the mass displaced the fat. Crescent-shaped fatty rinds are more frequently seen in peripheral nerve sheath tumors while circumferential fatty rinds are more commonly seen in hemangiomas. In the case of hemangiomas, this scenario does not fit the typical presentation of a hemangioma, since there is often a proliferation phase followed by involution in childhood. The split fat sign is more often seen in benign lesions or low-malignancy-grade tumors. It has been suggested that neurofibromatosis 1 tumors arise from the neurovascular bundles that are surrounded by fat and maintain the fat in the periphery as they grow.
Neurofibromatosis can be seen in 1/3000 people and is highly variable. Up to half of the cases can be familial. It can affect the skin, central nervous system, musculoskeletal system, and cardiovascular system. Neurofibromatosis can be benign or malignant.
Neither image shows abnormal vascularity, so venous malformation, hemangioma, and lymphatic malformation are less likely. Hemangiomas tend to show intravascular thrombi, vascular aneurysms, and venous components.
Glomus tumors are small masses that can be extremely painful with temperature change and typically affect the distal nail bed or palm. They would not have the presentation seen in this scenario.
2023
A 6-year-old boy is evaluated because of a scalp lesion. The lesion was present at birth and has not changed in character or appearance. A photograph is shown. The boy’s parents were told by their pediatrician that this lesion could become malignant. This patient has the highest risk for which of the following malignant tumors?
A) Basal cell carcinoma
B) Malignant melanoma
C) Merkel cell tumor
D) Pleomorphic dermal sarcoma
E) Squamous cell carcinoma
The correct response is Option A.
This is a nevus sebaceus (of Jadassohn), also known as an organoid nevus, a congenital malformation that arises from the pilosebaceous follicular units. It most commonly occurs in the scalp where it almost invariably presents as a flat, discolored plaque-like lesion with overlying alopecia. Over time, these lesions can thicken and transform into various benign tumors and malignant tumors. Benign tumors include syringocystadenoma papilliferum, trichoadenoma, and trichoblastoma, while the most common malignant tumor is basal cell carcinoma, followed a distant second by squamous cell carcinoma. While conventional wisdom once placed the rate of malignant transformation at 10 to 15%, current evidence suggests that the rate is significantly lower, especially in the pediatric population. Isolated nevus sebaceus should not be confused with nevus sebaceus syndrome, which is when a nevus sebaceus presents along with a more complex constellation of physical findings.
Malignant melanoma, pleomorphic dermal sarcoma, and Merkel cell tumor do not arise from nevus sebaceus.
2023
