Traumatic Tattoo: A Melanoma Mimic

A 58-year-old man became concerned when he first noticed a flat, dark area on his left upper arm. The lesion was set against a background of fairly severe photodamage. Family history was positive for melanoma (mother and 1 of 4 sisters).

Key point: The almost black nature of the lesion arouses suspicion for melanoma. This diagnostic concern is augmented by the variability in lesion color apparent on the close-up view. A conservative excisional biopsy, however, revealed this to be a traumatic tattoo (accidental or deliberate implantation of a dark-colored material, such as graphite or metal, into the dermis).

Treatment: The excisional biopsy led to complete removal, and thus served as definitive treatment.

Note: Many entities can be excellent clinical mimics. Histopathology is invaluable in determining the precise diagnosis.