A 48-year-old woman was admitted because of a mass and pain in the first web space of the hand dorsum, (). There was no history of trauma or rheumatoid disease. She noted that the mass had slowly grown in the last year. She had consulted many physicians, including a rheumatologist and orthopedist and she was diagnosed with a simple ganglion cyst, or tenosynovitis, and treated conservatively. Examination revealed a firm, very tender, 4.0 cm, lobular, soft tissue mass without crepitus in the dorsal aspect of the first web space of the hand. Pain was exaggerated by finger motion. Radiographs showed that the soft tissue mass shadow and the underlying bony cortex were normal and clearly separated from the lesion, (). In the STIR sequence, MRI demonstrated that chondral bodies surround the first web space and second flexor tendon, ().
Mass in the dorsal first web space of the hand.
Radiographs exhibited soft-tissue mass shadow and the underlying bony cortex were normal.
The MRI demonstrates that round separate chondral bodies surround the first web space and second flexor tendon (STIR sequence).
A benign synovial tumor with calcification was considered. The most likely diagnosis was primary synovial osteochondromatosis. Laboratory studies including hemograms and biochemical values were normal, and the patient underwent a debulking procedure. When a surgical exploration of the lesion was performed, numerous shiny soft corpuscles consistent with rice bodies were found in the first web space, extending distally through the sheath to the proximal side of the second finger, (). Histopathologic evaluation showed benign cartilaginous tissue with overlying scant synovial tissue consistent with tenosynovial chondromatosis, ().
Intraoperative photograph showing multiple rice bodies contained within the synovial sheath distally extending.
A nodule surrounded by the tenosynovial membrane (HE ×40).
The patient’s postoperative recovery was uneventful and she regained a full and painless range of motion in about two months. At the one-year follow-up, no underlying disorder was evident.