Osteoma of soft parts.

Osteomas of soft tissue are rare tumors. All previously reported cases occurred in the head, usually in the posterior tongue. We present two patients with soft-tissue osteomas in the thigh. Both masses were densely ossified and consisted of mature trabecular bone on computed tomography and magnetic resonance examination. Increased uptake of bone-seeking radiopharmaceutical was found on scintigraphy. Histologically, mature lamellar bone was seen with small amounts of cartilage seen in the periphery. Symptoms of mass effect which resolved following surgery were noted. We believe that this previously unrecognized soft-tissue appendicular neoplasm lies at the end of a spectrum of post-traumatic ossifying lesions which includes soft-tissue chondromas and osteochondromas, as well as myositis ossificans.