Pigmented basal cell cancer masquerading as superficial spreading malignant melanoma.

A 49-year-old woman of Spanish descent had a pigmented lesion on the thigh present for many years, which enlarged recently. The lesion showed notching and black, brown, and blue colors that led to the initial diagnosis of superficial spreading malignant melanoma. Results of skin biopsy disclosed the lesion was a basal cell epithelioma with large amounts of melanin in the dermis. This report illustrates the importance of considering pigmented basal cell epithelioma in the differential diagnosis of superficial spreading malignant melanoma.