Tendosynovial giant cell tumor of the patellar tendon sheath.

A 55-year-old woman presented with a 1-month history of anterior pain of the right knee. Magnetic resonance imaging showed a well-defined soft tissue mass in the fat pad posteriorly to the patellar tendon. An excisional biopsy was performed. Histologic examination showed tendosynovial giant cell tumor of the patellar tendon sheath. At the latest follow-up, there was no local tumor recurrence. [ABSTRACT FROM AUTHOR]