A broad shave biopsy, utilizing dermoscopy to help delineate the edges of the lesion, confirmed the diagnosis of melanoma in situ, superficial spreading type.
From the standpoint of ABCDE criteria (Asymmetry, Border irregularity, Color [varying shades or deep black color], Diameter > 6 mm, or Evolving/changing), this lesion was quite worrisome. Helpful clues on clinical exam included the asymmetry, border irregularity, color variations (brown, pink, and red), size, and history of change. A dermatoscope helped to refine the features of the lesion and highlighted the melanocytic-specific characteristics of its pigment network, streaks, and regression structures (pepper-like gray dots and white streaks).1
A broad shave biopsy allows a very thorough evaluation of such a heterogeneous lesion. A smaller punch biopsy can miss the most worrisome features. That said, a smaller punch biopsy is sometimes necessary in challenging anatomic locations, such as the palm or sole.
Patients given a diagnosis of melanoma in situ should undergo wide local excision with 5-mm margins or 1-cm margins in instances of lentigo maligna, which is a subtype of melanoma in situ with a higher risk of clinically uncertain margins. (A sentinel lymph node biopsy is not recommended for melanoma in situ, as the Breslow depth is 0 mm.)
For this patient, an in-office wide local excision was performed down to the fascia and the skin was repaired in a layered fashion. The plan for this patient was for him to return for skin examinations 3 to 4 times in the first year of diagnosis, followed by twice annually until he was 5 years from his diagnosis. After that, he would undergo annual skin exams.
Text courtesy of Jonathan Karnes, MD, medical director, MDFMR Dermatology Services, Augusta, ME. Photos courtesy of Jonathan Karnes, MD (copyright retained).