Extra-articular Tenosynovial Chondromatosis Mimicking a Neoplastic Disease in the First Web Space of the Hand.

Tenosynovial chondromatosis is a very rare disease. The most common symptom is a slowly enlarging soft tissue mass, which may be painful or cause limitation of joint motion. Plain radiograph may appear normal during early phases of the disease, but subsequent imaging may be necessary to exclude other pathologies. Nonoperative treatment may be elected for some patients, but a synovectomy and the removal of loose bodies are indicated for persistent symptoms. This report describe a case with a multinodular cartilaginous proliferation and rice body in the first web space of the hand, similar to synovial chondromatosis, but arising in the tenosynovial membranes.