Case report 705. Osteosclerotic sarcoidosis.

In summary, Sarcoidosis is a rare but well-recognized cause of diffuse osteosclerosis. The differential diagnosis of osteosclerosis is limited and includes osteoblastic metastases, sclerotic myeloma, myelofibrosis, and less common infiltrative bone marrow processes such as mastocytosis and sarcoidosis. In all of these entities the sclerosis is found most often in the axial (red marrow) skeleton. In this regard, it is interesting that cases of osseous sarcoid are usually lytic and located in the peripheral skeleton. In patients with osteosclerotic sarcoidosis, the diagnosis may be suggested by a past history of the disease or ancillary signs such as hilar node enlargement and subtle skin involvement. However, the specific diagnosis usually requires bone marrow biopsy with the demonstration of extensive, noncaseating granulomas.