Aneurysmal bone cysts.A clinicopathologic study of 66 cases

Sixty-six cases of aneurysmal bone cyst were reviewed clinically, pathologically and radiologically. Different therapies, including curettage, block excision, amputation and radiation therapy, and a new treatment, cryosurgery, were employed. Cryosurgery, which avoids the growth and neoplastic complications of radiation therapy and the loss of bone with block excision, had an extremely low rate of recurrence when compared to simple curettage. In manometric studies of 6 cysts, 3 had elevated vascular pressures as high as arteriolar levels. Thirty-two percent of the aneurysmal bone cysts had an accompanying benign primary lesion of bone. Based on these findings, a new hypothesis for the etiology and pathogenesis of aneurysmal bone cysts was proposed: a primary lesion of bone initiates an osseous, arteriovenous fistula and thereby creates, via its hemodynamic forces, the secondary reactive lesion of bone, which we term aneurysmal bone cyst.