Panniculitis ossificans traumatica of the lower leg.

Heterotopic bone formation in the skin, osteoma cutis, occurs in a variety of clinical settings. Primary osteoma cutis arises in otherwise unaffected skin, often in patients with systemic conditions, whereas secondary osteoma cutis is associated with cutaneous neoplasms and inflammation (metaplastic ossification). Metaplastic ossification almost exclusively affects the dermis. Presented is a patient with posttraumatic bone formation in the subcutaneous fat, panniculitis ossificans traumatica, an entity that has only rarely been reported.