Familial early onset sarcoidosis with bone cysts and erosions.

Early onset sarcoidosis is a granulomatous disease which is characterized by synovitis, polyarthritis, skin and eye involvement. We report the skeletal features of one patient with a family history and clinical symptoms suggestive of early onset sarcoidosis (EOS) which was confirmed by skin biopsy. Radiographs reveal postarthritic deformities of the MCP joints, contractures, a coarsened trabecular pattern at the PIP joints and small bone cysts resembling osteitis cystoides multiplex. Similar lesions were described in radiographs of the older sister and an uncle of our patient. This is the first report demonstrating bone cysts and erosions which could be a diagnostic feature in this rare disease and may help to differentiate other rheumatoid disorders.