Compression of the iliac vein by a synovial cyst.

While a synovial cyst of the hip is a rare cause of lower limb swelling, a differential diagnosis of deep vein thrombosis is needed. A case of lower limb swelling due to compression of the external iliac vein by a synovial cyst is presented with a review of the literature. Sagittal views and three-dimensional images of a CT scan were very useful for the diagnosis. This is the first review in English of vessel compression by a synovial cyst of the hip.