Atrophic dermatofibroma in an elderly male - a rarely described variant of a common lesion.

Dermatofibroma frequently presents as a red-brown nodule on the extremities of the middle aged. Atrophic dermatofibroma is a rare variant that has been most commonly described as an atrophic depressed, erythematous lesion in females. The correct diagnosis of atrophic dermatofibroma is often hindered by its infrequent presentation. It has a female preponderance with an occurrence ratio of 10:1. We describe a case of an atrophic dermatofibroma on the back of an elderly man. Skin biopsy demonstrated a spindle cell proliferation in a storiform pattern, loss of elastic fibers, and substantial atrophy of both the underlying dermis and subcutaneous tissue. An aggregation of elastic fibers was found in the periphery of the tumor. These histologic features supported the diagnosis of atrophic dermatofibroma. The dermal and adipocyte atrophy was likely responsible for the retracted appearance of the lesion.