Rare Presentation of Giant Cell Tumors of the Tendon Sheath: Bilateral Involvement of Tendoachilles.

Giant cell tumor of tendon sheath arises from the synovium of tendon sheaths, joints, or bursa, mostly affects adults between 30 and 50 years of age, and is slightly more common in females. It corresponds to a localized form of pigmented villonodular synovitis (PVNS). Typically occur in the hand where they represent the second most common type of soft tissue tumors after synovial ganglions. Bilateral giant cell tumor of tendon sheath of tendoachilles is a rare presentation. We report the case of a 22-years-old female presenting with pain in both ankles without any history of trauma. On clinical examination, tenderness on both tendoachilles and local indurations were observed. Ultrasonography showed focal thickening of Achilles tendon bilaterally, and Doppler demonstrated increased flow in peritendinous area. MRI findings showed that most of the tumor had intermediate signal intensity and portions of the tumor had low signal intensity. Fine needle aspiration cytology confirmed the diagnosis of giant cell tumor of tendon sheath. Excision biopsy was done with no recurrence on subsequent follow-up.