A 32-year-old woman sought medical attention after noticing a change in the appearance of a mole on her leg. The lesion was asymptomatic. Her family history was negative for melanoma.
Key point: Any morphologic alteration in a pigmented lesion requires careful and timely attention. In this case, the odd appearance (eccentric placement of a new, dark macule at the superior pole of a preexisting nevus) justified an excisional biopsy. Histology revealed an in situ malignant melanoma.
Treatment: Current standard of care for in situ melanoma dictates wide and deep excision with a 0.5-cm margin. Neither sentinel lymph node biopsy nor laboratory tests are indicated.
Note: The lower leg is one of the highest-risk areas for melanoma development in a woman.