Melanoma Flashcards
A 60-year-old man comes to the office because of a 2-cm pigmented lesion on the right lower back that has enlarged progressively for 3 years. No lymph nodes are palpable. Examination of a specimen obtained on punch biopsy shows a Clark Level IV malignant melanoma with a Breslow thickness of 1.2 mm and ulceration. Which of the following is the most appropriate management?
A) Excision with 2-cm margins
B) Preoperative lymphoscintigraphy, sentinel lymph node biopsy, and excision with 1-cm margins
C) Preoperative lymphoscintigraphy, sentinel lymph node biopsy, and excision with 2-cm margins
D) Excision with 1-cm margins, followed by lymphoscintigraphy and sentinel lymph node biopsy at a later date
E) Excision with 3-cm margins, split-thickness skin grafting, and right axillary lymph node dissection
C) Preoperative lymphoscintigraphy, sentinel lymph node biopsy, and excision with 2-cm margins
A melanoma 1.2 mm in thickness on the lower back would best be excisedwith 2-cm margins and a concurrent sentinel lymph node biopsy. Although a few studies cite the adequacy of a 1-cm margin for tumors less than 2 mm in thickness, a punch biopsy was performed in he scenario described, and the final pathology of the complete lesion could show a thicker lesion. In a location where there is sufficient tissue, a 2-cm margin is more appropriate for a lesion that is over 1 mm in thickness. Most authors cite resection margins of 5 mm for melanoma in situ, 1 cm for melanoma less than 0.8 mm, and 2 cm for melanoma between 0.8 and 4 mm.
Most authors cite resection margins of _____ for melanoma in situ
Most authors cite resection margins of 5 mm for melanoma in situ, 1 cm for melanoma less than 0.8 mm, and 2 cm for melanoma between 0.8 and 4 mm.
Most authors cite resection margins of _____ for melanoma less than 0.8 mm
1 cm for melanoma less than 0.8 mm
Most authors cite resection margins of _____ for melanoma between 0.8 and 4 mm
2 cm for melanoma between 0.8 and 4 mm.
Margins cited for melanoma sizes
Most authors cite resection margins of 5 mm for melanoma in situ, 1 cm for melanoma less than 0.8 mm, and 2 cm for melanoma between 0.8 and 4 mm.
Patients with intermediate thickness lesions of 0.8 mm to 4 mm have a ______% incidence of microscopic regional disease.
Patients with intermediate thickness lesions of 0.8 mm to 4 mm have a 20 to 25% incidence of microscopic regional disease. S
Sentinal lymphadenectomy for melanoma
In patients with melanomas greater than or equal to 1 mm in thickness and no clinical evidence of regional lymph node metastases, lymphoscintigraphy is performed preoperatively to define the lymphatic drainage and demonstrate sentinel lymph node location. Sentinel lymphadenectomy is performed most accurately at the time of wide and deep excision of the primary lesion. Later,sentinel lymph node localization may be impaired if the primary lesion has been excised deeply, as the drainage patterns may have been altered by the previous procedure.
When should preoperative lymphoscintigraphy be performed for melanoma?
It is imperative to obtain preoperative lymphoscintigraphy in areas with a high likelihood of aberrant drainage patterns. In the trunk, unpredictable drainage patterns can occur in 20 to 35% of cases.
A 65-year-old Caucasian man comes to the office because of a dark, pigmented lesion on the thumb that he first noticed 3 months ago. There is no history of trauma to the digit. Physical examination shows a variegated lesion with asymmetrical borders in the germinal matrix of the nail bed of the right thumb. Which of the following is the most appropriate first step in management? A ) Amputation to next joint B ) Radiation therapy C ) Shave biopsy D ) Wide excision E ) Observation
C ) Shave biopsy
This pigmented lesion in the patient described could be a post-traumatic subungual hematoma, benign nevus, or subungual melanoma, or benign melanonychia striata longitudinalis. Evaluation of a suspiciously pigmented lesion in the nail bed should commence with a shave biopsy of the lesion. The lesion has been present for 3 months and has not grown out to the sterile matrix; because the patient says there has been no previous trauma, further observation would be inappropriate.
Wide excision or amputation is not warranted until an attempt at diagnosis has been completed. T
Evaluation of a suspiciously pigmented lesion in the nail bed should commence with:
Evaluation of a suspiciously pigmented lesion in the nail bed should commence with a shave biopsy of the lesion.
Melanonychia striata longitudinalis
Benign streaks in the nail plate (melanonychia striata longitudinalis) are extremely common in African American patients and often occur spontaneously with advancing age.
Core biopsy to evaluate nail bed lesion
Evaluation of a suspiciously pigmented lesion in the nail bed should commence with a shave biopsy of the lesion. A core biopsy of the germinal matrix could produce a nail bed and plate abnormality.
Furthermore, there is no need for a core biopsy to determine the depth of the lesion, as the histology and staging of the nail bed are different from the skin.
How long does it take for the nail plate/matrix to grow to the tip after an injury?
After an injury, the nail plate and corresponding matrix grow to tip by 3 to 4 months.
Nailbed: treatment for melanocytic hyperplasia without atypia
Melanocytic hyperplasia without atypia is considered benign and can be observed.
Nailbed: atypia or melanoma in situ
The presence of atypia or melanoma in situ requires complete excision with clear margins. The wound is closed with a full-or split-thickness nail bed graft.
Acral-lentiginous melanoma represent ___ of all cutaneous melanomas
Acral-lentiginous melanoma is found beneath the nail, on the palm of the hand, or on the sole of the foot. These lesions represent approximately 3% of all cutaneous melanomas.
Prognosis of acral-lentiginous melanoma vs others
The prognosis for subungual melanomas is worse than for other cutaneous melanomas, probably because of delayin diagnosis.
When symptoms occur with acral lentiginous melanoma, _____% have metastases
When symptoms occur, 25 to 30% of patients have metastases.
Treatment of subungual hand melanomas
Treatment of subungual hand melanomas consists of amputation through the joint, just proximal to the lesion. Volar flaps are used for the closure of the defect.
Special consideration when amputating for thumb - subungual hand melanoma
For lesions of the thumb, deepening the first space with local z-plasty is recommended to improve function.
Which of the following additional findings in the patient shown is indicative of the most life-threatening syndrome? A ) Hydrocephalus B ) Large or multiple axial nevi C ) Posterior midline nevi D ) “Satellite” nevi E ) Underdevelopment of a limb
A ) Hydrocephalus
Neurocutaneous melanosis connotes the association of a large axial CMN with the CNS involvement.
At least two thirds of those who present with or develop symptomatic CNS disease succumb to the disease process, either because of inexorable “benign” proliferation of melanocytes in the leptomeninges and brain or as a result of malignant degeneration.
Symptomatic hydrocephalus may necessitate the placement of a ventriculoperitoneal or ventriculojugular shunt. Unfortunately, following malignant transformation in the CNS, such shunts afford the malignant melanocytes ready access to the systemic circulation, leading to a rapid demise
Congenital melanocytic nevi (CMN)
Congenital melanocytic nevi (CMN) are birthmarks that are present at birth or become apparent within the first year of life. They are found in 1% to 2% of the general population. CMN are one of several known risk factors for development of melanoma.
Where do melanomas associated with congenital melanocytic nevus occur?
Interestingly, 50% of the melanomas that develop occur within the nevi, but the other 50% occur within the central nervous system (CNS) or within normal skin.
What % of pediatric melanomas are associated with giant congenital melanocytic nevi
Despite significant increase in risk, giant CMN-associated melanomas still account for less than 3% of all pediatric melanomas
Neurocutaneous melanosis
NCM connotes the association of a large axial CMN with the CNS involvement. CNS manifestations may present as hydrocephalus, seizures, focal deficits, or partial paresis. The majority of those children with NCM who manifest such problems do so before 2 years of age.
Prognosis of neurocutaneous melanosis (displaying neurologic symptoms)
At least two thirds of those who present with or develop symptomatic CNS disease succumb to the disease process, either because of inexorable “benign” proliferation of melanocytes in the leptomeninges and brain or as a result of malignant degeneration.
Symptomatic hydrocephalus may necessitate the placement of a ventriculoperitoneal or ventriculojugular shunt. Unfortunately, following malignant transformation in the CNS, such shunts afford the malignant melanocytes ready access to the systemic circulation, leading to a rapid demise
To identify which patients with congenital melanocytic nevi may have CNS involvement, a number of risk factors have been identified:
Presence of large or multiple axial CMN or both
Nevi on the posterior midline
Presence of multiple satellite nevi
MRI with gadolinium contrast has proved to be a particularly sensitive method for detecting the presence of CNS involvement by melanocytes in such patients. MRI can detect occult neurologic involvement even in infants who are clinically normal.
A 42-year-old man has Clark Level III melanoma with a Breslow thickness of 1.5 mm in the concha of the right ear. Physical examination shows no other palpable masses. In addition to wide excision of the lesion, which of the following is the most appropriate step in management?
A ) Infraclavicular lymph node dissection
B ) Posterior neck dissection
C ) Sentinel lymph node biopsy
D ) Superficial parotidectomy
E ) Total parotidectomy with radical neck dissection
C ) Sentinel lymph node biopsy
Sentinel lymph node biopsy, which also serves to stage the extent of disease, is the most appropriate management after wide excision of the lesion. It is the most specific means of identifying regional lymph node spread. The sentinel node may be located in the parotid gland, the infraclavicular node, or some other part of the cervical chain of lymph nodes.
A 9-month-old female infant has an 11-cm congenital melanocytic nevus. The patient is at greatest risk for malignant transformation of which of the following systems? (A)Central nervous (B)Endocrine (C)Gastrointestinal (D)Skeletal (E)Urologic
(A)Central nervous
In addition to melanoma, patients with large, congenital melanocytic nevi are at increased risk for developing neurocutaneous melanocytosis, in which collections of melanocytes are present in the leptomeninges. Malignant transformation also can occur in neurocutaneous melanosis and result in primarycentral nervous system (CNS) melanoma. Even without malignant transformation, neurocutaneous melanosis can carry significant morbidity and mortality, often from seizures, hydrocephalus, and other signs of CNS irritation.
Other than CNS melanoma, the incidence of _____________ is also increased in patients with large, congenital melanocytic nevi.
The incidence of rhabdomyosarcoma is also increased in patients with large, congenital melanocytic nevi.
A 45-year-old man comes to the office because he has a one-year history of a dark streak on the nail of the thumb of the nondominant left hand. Biopsy of the specimen of involved nail bed tissue shows 1-mm-thick malignant melanoma. Which of the following is the most appropriate surgical intervention?
(A)Mohs micrographic surgery
(B)Wide soft-tissue excision
(C)Amputation at the interphalangeal joint
(D)Amputation at the mid metacarpal joint
(E)Ray amputation
(C)Amputation at the interphalangeal joint
The nail bed is unique because it is directly adherent to the underlying distal phalanx periosteum. Early studies recommended metacarpal or metacarpal ray amputations for invasive melanoma; however, recent studies have shown the efficacy of more conservative amputations without altering survival rate or local recurrence rate. Treatment goals are eradication of the tumor and preservation of function. Therefore, amputation at the level just proximal to the disease is recommended.
Why is the nail bed unique for melanoma / aggressive treatment?
The nail bed is unique because it is directly adherent to the underlying distal phalanx periosteum.
Which of the following percentages best represents the risk of transformation of a congenital giant nevus to malignant melanoma? (A)10% (B)20% (C)30% (D)40% (E)50%
(A)10%
Although it is generally accepted that giant congenital nevi may undergo transformation to malignant melanoma, the exact incidence is difficult to determine, due in part to limitations in methodology of the available studies. Recent reports cite an incidence ranging from 2.9% to 12.2%
Which giant congenital nevi are at greatest risk for malignant transformation?
Giant congenital nevi at greatest risk for transformation to melanoma are those lesions that have a predicted largest diameter of 20 cm in adulthood.
What are the precursor lesions for malignant melanoma?
Congenital melanocytic nevi
Common acquired melanocytic nevi
Dysplastic nevi
Melanoma in situ
Which of the following skin lesions meets criteria for sentinel lymph node biopsy (SLNBx)?
(A)Basal cell carcinoma (8 cm wide) on the anterior chest
(B)Melanoma (1.6 mm thick) of the breast with bulky axillary adenopathy
(C)Melanoma-in-situ on the shoulder
(D)Squamous cell carcinoma (1.8 cm wide) on the dorsum of the hand
(E)Squamous cell carcinoma (2 cm wide) in a 26-year-old burn scar of the foot
(E)Squamous cell carcinoma (2 cm wide) in a 26-year-old burn scar of the foot
Sentinel lymph node biopsy (SLNBx) is a well-established staging procedure for melanoma and breast cancer. A patient with melanoma in situ, by definition, does not have invasion and, therefore, would not benefit from SLNBx. Conversely, the patient with bulky adenopathy most likely has regional metastatic disease and requires formal lymphadenectomy. Indications for SLNBx in non-melanoma skin cancers are evolving and currently include squamous cell carcinoma greater than 2 cm in diameter, Merkel cell carcinoma, and Marjolin ulcer (burn scar carcinoma). Basal cell carcinomas almost never demonstrate lymphatic spread; therefore, SLNBx would not add any diagnostic information
Basal cell carcinomas and SLNBx
Basal cell carcinomas almost never demonstrate lymphatic spread; therefore, SLNBx would not add any diagnostic information
Non-melanoma skin cancers and SLNBx
Indications for SLNBx in non-melanoma skin cancers are evolving and currently include squamous cell carcinoma greater than 2 cm in diameter, Merkel cell carcinoma, and Marjolin ulcer (burn scar carcinoma)
Melanoma in situ and SLNBx
A patient with melanoma in situ, by definition, does not have invasion and, therefore, would not benefit from SLNBx
A 73-year-old man is referred to the office by his primary care physician for evaluation of discoloration of the nail of the left thumb, which has been present for the past seven years. The patient says the appearance of the nail has not changed recently. Biopsyof the nail matrix shows malignant melanoma of indeterminate depth. Which of the following surgical procedures is the most appropriate management?
(A)Elective lymph node dissection and amputation at the metacarpophalangeal joint
(B)Elective lymph node dissection and nail ablation
(C)Sentinel node biopsy and amputation at the level of the interphalangeal joint
(D)Sentinel node biopsy and excision of skin with 1-cm margins
(E)Sentinel node biopsy and ray amputation of the carpometacarpal joint
(C)Sentinel node biopsy and amputation at the level of the interphalangeal joint
Because of the proximity of the nail matrix to the periosteum and bone, adequate resection margins are not achieved with standard wide excision of 1 to 2 cm, and recommendation for excision is at the distal interphalangeal joint of the finger or interphalangeal joint of the thumb. Melanoma can track along the neurovascular bundles.
Sentinel node biopsy has become the standard of care, and since its advent, elective lymph node dissection is no longer recommended.
Approximately _____% of subungual melanomas may be amelanotic.
Approximately 20% to 25% of subungual melanomas may be amelanotic.
Amputation more proximal than the proximal joint for subungual melanoma
Amputation at a more proximal level is not needed and does not improve prognosis. Moreproximal amputation also results in a critical loss of function, particularly concerning the thumb.
An area of pigmentation in the ________ is almost pathognomonic for subungual malignant melanoma.
An area of pigmentation in the eponychium is almost pathognomonic for subungual malignant melanoma.
A 60-year-old man is diagnosed with melanoma of the forehead. In addition to wide local excision, in which of the following tumor stages is sentinel lymph node biopsy indicated? (A)Tis N0 M0 (B)T2a N1 M0 (C)T2b N0 M0 (D)T3b N1 M0 (E)T4a N0 M1
(C)T2b N0 M0
Sentinel lymph node biopsy (SLNB) is the standard of care for intermediate-thickness melanoma, with clinically negative nodes.
T4 is a deep melanoma and is not appropriate for SLNBx.
Importance of SLNB for melanoma
Guides adjuvant systemic protocols