The use of CT scan in the evaluation of non-popliteal synovial cysts about the knee.

We investigated the diagnostic approach to non-popliteal synovial cysts about the knee. Included were all cases that occurred at the Wilford Hall USAF Medical Center in the past 5 years. The five patients all presented with a mass about the knee. The history and physical exam placed synovial cyst high on all five differential lists. All patients had a CT scan, and the CT failed to identify the cystic nature of the mass in any of them. We conclude that the CT scan is not useful in the evaluation of suspected non-popliteal synovial cysts about the knee.