Tumorous Calcification Causing Carpal Tunnel Syndrome

PURPOSE: There is little information on solitary tumorous calcification causing carpal tunnel syndrome in the literature. This study describes our experience with surgically treated cases of solitary tumorous calcification causing carpal tunnel syndrome. METHODS: Seven patients with symptomatic carpal tunnel syndrome who had tumorous calcification in the carpal tunnel confirmed by radiographical examinations and had then undergone open incisional carpal tunnel release were reviewed. The precise location and the appearance of the calcified mass were confirmed with the preoperative radiographic examinations and the operative records. The additional histology and the composition analysis of the calcified mass were also reviewed in five removed calcifications. RESULTS: Radiographs of each hand revealed a mass of calcification lying anterior to the capitate bone in the carpal tunnel. Intraoperatively, an oval calcified nodule, measuring 10 × 10 × 10 - 18 mm, was observed overlying the capitate, attached firmly to the palmar radiocarpal extrinsic ligament. A composition with an average of 60 % basic calcium phosphate was revealed by infrared absorption spectrometry. Histological sections showed a calcified deposit surrounded by fibrocartilagenous tissue in three cases. CONCLUSION: These facts suggest that the pathogenesis of tumorous calcification causing carpal tunnel syndrome is comparable with that of calcifying tendinitis of the rotator cuff in which a cell-mediated reactive process plays an important role at the tendon insertion.