REPORT OF A CASE
A 72-year-old white man was referred for evaluation and treatment of an inflamed skin tag on his neck. A thrombosed, erythematous, pedunculated skin tag was found on the left side of his neck. In addition, an erythematous, slightly scaly plaque with sharply but irregularly demarcated borders (3×5 cm) was found on the right upper abdomen (Figure 1 and Figure 2). The lesion was completely asymptomatic and of at least 1 year's duration. The rest of the skin examination was normal. The skin tag was removed with a shave excision. A punch biopsy specimen was taken from the indurated plaque; light microscopic findings from the specimen are shown in Figure 3 and Figure 4.What is your diagnosis?Figure 1.Figure 2.Figure 3.Figure 4.
DIAGNOSIS:
Amelanotic melanoma.
HISTOPATHOLOGIC FINDINGS AND CLINICAL COURSE
Histopathologic findings revealed melanocytes with marked cytologic atypia scattered within the epidermis. The