Tenosynovial giant cell tumor (TGCT), also known as pigmented villonodular synovitis, is a benign proliferative disorder that most commonly affects large joints. Involvement of the wrist is rare, and purely intra-articular presentation is exceptional, often leading to delayed or missed diagnosis.

We report the case of a male patient with long-standing dorsal wrist pain associated with what was believed to be a recurrent ganglion cyst. Initial ultrasound and magnetic resonance imaging (MRI) examinations in 2021 identified only a dorsal ganglion cyst, although a nodular intra-articular lesion compatible with TGCT was retrospectively visible on both MRI studies and not reported. Persistent symptoms led to repeat imaging in 2023 and 2025, where the latest eventually suggested intra-articular TGCT. The patient underwent wrist arthroscopy in 2025, which revealed extensive pigmented nodular synovial proliferation. Complete arthroscopic excision and synovectomy were performed. Histopathological analysis confirmed the suspicion. Early postoperative evolution was favorable, with pain relief and recovery of function.

Intra-articular TGCT of the wrist is a rare but important differential diagnosis in patients with persistent wrist pain, particularly when symptoms are disproportionate or recur after treatment of more common conditions such as ganglion cysts. Wrist arthroscopy allows direct visualization, definitive diagnosis, and minimally invasive treatment, with the additional benefit of early rehabilitation.