Intra-articular tenosynovial giant cell tumor arising from the posterior cruciate ligament.

Tenosynovial giant cell tumors originate from the synovial tissue of the joints, tendon sheaths, mucosal bursas, and fibrous tissues adjacent to tendons. The disease presents in localized and diffused forms. Large joints, such as the knee, are not frequently affected. Magnetic resonance imaging has been reported to be the best noninvasive technique to diagnose these tumors. Magnetic resonance imaging diagnosis has to be confirmed by histopathological examination. Few reports exist of tenosynovial giant cell tumors arising from the posterior cruciate ligament. This article describes a case of an 18-year-old man with no history of trauma but with a 2-year history of mild, ongoing, and worsening right knee pain and swelling localized in the popliteal region. Clinical examination of the knee was negative. Magnetic resonance imaging revealed an intra-articular mass measuring 4.8×2.1×2.7 cm in the posterior region of the knee attached to the posterior cruciate ligament. Arthroscopy was performed using the posterior approach through the posterolateral and posteromedial portals. A specimen of the lesion was removed arthroscopically for histopathological examination, and a wide resection of the mass was performed with a shaver and a radiofrequency ablation device. Histopathological examination confirmed the diagnosis of a tenosynovial giant cell tumor. No recurrence had occurred at 2-year follow-up. Magnetic resonance imaging and histopathological examination may help in achieving a correct diagnosis, and arthroscopic excision using a posterior approach may be the treatment of choice by surgeons.