Tenosynovial giant cell tumors (TGCT) are a rare group of generally non-malignant tumors that involves the synovium and tendon sheath. A young female patient presented to the outpatient department with a complaint of unilateral knee swelling and pain. She was evaluated as such and based on a provisional diagnosis of benign synovial proliferation, she was treated with an arthroscopic resection. We discuss our case and discuss the possible medical therapies to prevent recurrence.