We report the case of an 80-year-old woman who presented with an asymptomatic slowly growing mass in the dorsal aspect of her right wrist. Radiographs revealed a snail-shaped radiopaque structure. Surgical exploration and resection revealed a calcified lesion over the extensor digitorum communis.Histopathological analysis confirmed the diagnosis of tenosynovial chondromatosis. At last follow-up, 4 years after surgery, the patient was asymptomatic and free of recurrence. Practitioners and hand surgeons should be aware of dorsal involvement and radiological calcifications suggestive of tenosynovial chondromatosis, which is a rare benign soft tissue neoplasm that can affect all tendon sheaths of the hand.