ENCHONDROMA IN A PATIENT WITH FIBRODYSPLASIA OSSIFICANS PROGRESSIVA

Fibrodysplasia ossificans progressiva (FOP) is a rare heritable disord er characterized by progressive heterotopic endochondral bone formatio n arising in ligament, tendon, and the fibrous connective tissue of sk eletal muscle. The disorder is almost invariably associated with skele tal malformations of the endochondral anlage of the feet. A 25-year-ol d woman with FOP had a histopathologically documented phalangeal encho ndroma. This common neoplasm of cartilage and bone seems not to have b een previously reported in FOP; it may represent a coincidental occurr ence, but in the context of the patient's genetic disorder, an enchond roma may represent an unusual and variable expression of the disease.