Proximal tibiofibular joint synovial cyst--one pathology with three different presentations.

Synovial cysts of the proximal tibiofibular joint are less common than synovial cysts of the knee joint but may present in a similar fashion and may be difficult to diagnose clinically. We report three cases of such synovial cysts: (1) the synovial cyst presented as an asymptomatic lump distal to lateral joint line of the knee; (2) the synovial cyst presented as a mass fluctuating in size with intermittent symptoms; (3) a man with a large mass in proximal anterior leg and drop foot. The patients were operated. The first and the third patients were treated successfully without recurrence, and complete recovery of the proneal nerve in third case ensued. The synovial cyst recurred in the second case; however, the patient refused a second operation. Age distribution and clinical manifestation of extraneural proximal tibiofibular joint synovial cyst is discussed in the light of relevant literature.