[Unusual causes of the carpal tunnel syndrome]

In 193 cases of carpal tunnel exploration, carried out because of compression of the medium nerve, we have encountered 15 unusual findings (7.8%). This emphasizes the necessity for thorough exploration of the carpal tunnel. Four unusual disease processes are described, which led to a median compression syndrome: Tuberculous tenosynovitis, lipomatous hyperplasia, chondroma of a superficial flexor tendon and monofascicular neurinoma of the median nerve.