A Rare Variant Dermatofibroma with Risk for Local Recurrence and Metastasis

Benign fibrous histiocytomas (FH; also known as dermatofibromas) are among the most common soft-tissue tumors. The range of the histology is wide, encompassing epithelioid, lipodized, palisading, cellular, aneurismal, and myxoid features, among others. Deep-type FH was first described 20 years ago. Although most dermatofibromas involve the dermis predominantly, the deep variant involves the subcutis with extension to the deep reticular dermis.

These authors retrospectively reviewed the clinicopathologic presentation of 69 deep FHs seen at a tertiary care hospital. In these patients (41 men; median age, 37), most tumors occurred on the lower extremities. All tumors contained ovoid or spindle cells. The authors found multinucleated giant cells…