title: Serum CA-125 in the evaluation of benign adnexal cysts.
abstract: Because serum CA-125 concentrations are increased in women with endometriosis, our objective was to determine whether CA-125 levels could be used to differentiate endometriotic from nonendometriotic benign cysts. During a 2-year period, all women who had an endometrioma (n = 33) or a nonendometriotic cyst (n = 27) that was greater than or equal to 4 cm were included. Serum CA-125 levels were measured by an immunoradiometric assay, and the mean concentrations in women with an endometriotic cyst increased as the diameter of the cyst increased. The mean CA-125 concentrations in women with cysts greater than or equal to 4 cm were 53 +/- 2 U/ml in 19 women with an endometriotic cyst, 11 +/- 1 U/ml in 20 women with a nonendometriotic cyst, and 15 +/- 1 U/ml in 7 women with a nonendometriotic cyst and endometriosis. In the fluid of 10 endometriomas, the mean CA-125 concentration was 290 +/- 94 X 10(3) U/ml (range 10 to 900 X 10(3) U/ml). With cysts diameters greater than or equal to 4 cm, 19 of 19 women with endometriotic cysts, zero of seven women with nonendometriotic cysts and endometriosis, and zero of 20 women with nonendometriotic cysts had CA-125 concentrations greater than or equal to 20 U/ml (99% upper normal limit). We conclude that serum CA-125 determinations offer an excellent method to differentiate endometriotic from nonendometriotic benign cysts.
mesh_terms: D000328:Adult; D000951:Antigens, Neoplasm / Q000032:analysis*; D000954:Antigens, Surface / Q000032:analysis; D015295:Antigens, Tumor-Associated, Carbohydrate; D003937:Diagnosis, Differential; D004715:Endometriosis / Q000097:blood*; D005260:Female; D006801:Humans; D010048:Ovarian Cysts / Q000097:blood*; D010051:Ovarian Neoplasms / Q000097:blood*
chemical_list: D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D015295:Antigens, Tumor-Associated, Carbohydrate