Ovarian endometriosis associated with ovarian carcinoma: A clinicopathological and immunohistochemical study

Objective. The purpose of this study was to demonstrate the incidence, the histopathological characteristics, and the proliferation activity of endome triosis and atypical endometriosis associated with ovarian carcinoma. Methods. Microscopic slides of primary lesions from 127 patients with prima ry ovarian carcinoma were reviewed. The presence or absence of endometriosi s and the transitions from typical endometriosis to atypical endometriosis and from atypical endometriosis to carcinoma were also histologically evalu ated. Ki-67 immunoreactivity of typical and atypical endometriosis and carc inoma was examined. In addition, endometrial metaplasias were also evaluate d. Results. Of the 127 patients, 37 had endometriosis: 70% (30/43) had clear c ell adenocarcinoma, 43% (3/7) had endometrioid adenocarcinoma, 7% (4/60) ha d serous adenocarcinoma, and none (0/17) had mucinous adenocarcinoma. Thirt y-three cases showed typical endometriosis and 29 cases had atypical endome triosis (25 cases had both). Tufting and the stratification of the lining e pithelium were observed in 25 and 23 cases, respectively. The transition fr om typical endometriosis to atypical endometriosis was observed in 22 cases , and the transition from atypical endometriosis to carcinoma, in 23 cases. Only one case showed a direct transition from typical endometriosis to car cinoma. The mean Ki-67 indices were as follows: ovarian carcinoma, 23.1; at ypical endometriosis, 9.9; typical endometriosis, 2.7. In 18 cases with met aplasia in endometriosis, eosinophilic metaplasia and ciliated metaplasia w ere the most common types. Five cases had two types of metaplasia. Conclusions. Ovarian carcinomas, especially clear cell and endometrioid ade nocarcinomas, are highly associated with endometriosis. Atypical endometrio sis shows proliferation activity intermediate to those of typical endometri osis and ovarian carcinoma, suggesting it is a precancerous status. (C) 200 0 Academic Press.