Differential diagnosis between uterine myoma and endometriosis using CA 125 as a new tumor marker of ovarian carcinoma.

For a preoperative differentiation between leiomyomata uteri and adenomyosis, we measured serum levels of the antigen CA 125, which is specific to ovarian non-mucinous epithelial carcinoma, in patients with benign gynecologic diseases (39 leiomyomata uteri, 10 adenomyosis, 4 adenomyosis with leiomyomata uteri, 3 adenomyosis with external endometriosis and 4 external endometriosis). Using radio-immunoassay (RIA) kit, we found the normal range of CA 125 levels to be below 34 U/ml. The mean CA 125 level (±S.D.) was 20.3 ± 10.3 U/ml in patients with leiomyomata uteri and 151.2 ± 157.3 U/ml in those with adenomyosis. The mean CA 125 level in patients with leiomyomata uteri was not statistically higher than that in disease-free women. The mean CA 125 level in patients with adenomyosis was statistically higher than that in disease-free women. Of 17 patients with surgically demonstrable adenomyosis, the CA 125 values were over 34 U/ml in 16 (94.1%). Three (75%) of 4 patients with surgically demonstrable external endometriosis had a serum CA 125 level in excess of 34 U/ml. Of 39 patients with surgically demonstrable leiomyomata uteri, CA 125 levels were below 34 U/ml in 37 (94%). CA 125 levels in patients with adenomyosis gradually decreased postoperatively and all were below 34 U/ml within four weeks. Using this approach, leiomyomata uteri and adenomyosis can be differentiated preoperatively and the response to treatment in patients with endometriosis can be monitored.