Hemosiderotic (pigmented) atypical fibroxanthoma mimicking malignant melanoma.

Atypical fibroxanthoma is a rare cutaneous malignancy that usually presents as a rapidly growing red papule on the head and neck in elderly white males. Several variants have been described. We report a patient who presented with a slowly enlarging pigmented lesion on his left ear that was clinically worrisome for malignant melanoma. Histopathologic evaluation with immunohistochemistry revealed an unusual case of hemosiderotic pigmented atypical fibroxanthoma. The tumor was successfully extirpated with Mohs micrographic surgery, with no recurrence at 6-month follow-up.