A Rare Case of Giant Cell Tumour of Tendon Sheath and Its Arthroscopic In Toto Excision.

The aim of this study is to bring attention to a unique occurrence in an uncommon location and to describe our approach to treatment in this context. We describe a case of a 36-year-old male who presented with complaints of pain in his left knee for three months, with a restricted range of motion, without a prior history of trauma. A thorough knee examination was performed, which was unremarkable except for a restricted range of motion and tenderness along the medial joint line. A plain radiograph of the knee revealed no bony injury. MRI was done to assess the extension and it confirmed a soft tissue mass beneath the patella. The patient was taken up for surgery after a pre-anesthetic checkup and the mass was removed arthroscopically in toto using a higher accessory antero-medial portal. The mass was removed with the help of a spatula without damaging it and sent for histopathological analysis. Histopathology confirmed that it was a giant cell tumour of the tendon sheath. The procedure was uneventful, and the patient achieved a full range of motion post-operatively.