Synovial lipoma arborescens of the hip.

Lipoma arborescens is a rare intra-articular tumor usually found in the knee joint. The reported lesion involved the inferomedial recess of the right hip synovium, in a 29-year-old male. The clinical findings were nonspecific. Both arthrography and computerized tomography (CT) of the hip disclosed the tumor which, on CT examination, showed an inhomogeneous low density, due to its fat content. The final diagnosis was given by histological examination of the resected mass. No recurrence was observed after one year. The long-term prognosis probably depends more on the underlying disorder of the joint than on the lipoma itself.