Synovial cysts and sarcoid synovitis.

The case of a practice nurse who presented with painless cystic swellings in the popliteal and antecubital fossae and lymphoedema of the legs is reported. Biopsies of synovium, a breast lump, axillary lymph nodes and of the Kveim site demonstrated sarcoidosis. Prior to biopsy diagnosis was not obvious. Synovial cysts are a very rare manifestation of sarcoid joint disease and this case illustrates the importance of biopsy in establishing the diagnosis.