The expression of estrogen receptors in the tenosynovium of postmenopausal women with idiopathic carpal tunnel syndrome.

The purpose of this study was to investigate estrogen receptor (ER) expression in tenosynovial tissues of postmenopausal woman with idiopathic carpal tunnel syndrome (CTS) to determine whether estrogen contributes to the pathogenesis of this condition. Biopsy samples of tenosynovial tissues were collected from 14 postmenopausal women (mean age; 57, range; 46-69 years) undergoing surgery for idiopathic CTS, and control specimens of tenosynovial tissue were collected from 6 postmenopausal women (mean age; 59, range; 48-68 years) without CTS. Histological and immunohistochemical examinations were performed to determine the distributions of ER-α and ER-β in tenosynovial tissues. Histological examinations showed a significant increase in fibroblast cell densities in the specimens from the carpal tunnel syndrome patients. ER-α and ER-β immunoreactivities were observed in fibroblasts and in the synovial lining cells of tenosynovial tissues, and these were significantly greater in patients than in controls. This study suggests that the up-regulations of ERs in the tenosynovial tissue are associated with idiopathic CTS in postmenopausal women.