Ovarian endometrioid adenofibromatous and cystadenofibromatous tumors: benign, proliferating, and malignant.

Ovarian endometrioid tumors with an adenofibromatous pattern have been described but the entire spectrum of these tumors has not been analyzed. A series of ten cases was studied and divided into two benign, four proliferating, and four malignant tumors on the basis of their morphologic characteristics. The most useful criterion for distinguishing proliferating from benign adenofibromatous tumors is increased epithelial proliferation, associated with glandular complexity and crowding in the former. Proliferating tumors may represent one form of the endometrioid tumor of borderline malignancy. The presence of a confluent growth pattern with invasion of the stroma distinguishes malignant from proliferating tumors. The various tumors in this group frequently show squamous metaplasia and are often associated with endometriosis. Because of the relatively small series, the biologic behavior of these histologic variants cannot be evaluated at this time.