Pelvic endometriosis is rarely associated with ovarian borderline tumours, cytologic and architectural atypia: a clinicopathologic study.

Endometriotic foci, especially ovarian ones, with epithelial cytologic atypia may be precursors of cancer. This study presents an overview of the atypical cytological and histopathological findings associated with endometriosis. Six cases of endometriosis, with atypical histological and cytological changes, were obtained from the archives of the Department of Pathology at Cleveland Clinic Foundation between year 2000 and 2003. The size of the base from which these cases were drawn was 2000 cases of endometriosis. The age range of the patients was from 29 to 52 years. The clinical presentations included infertility (three cases), pelvic pain (three cases), adenexal and pelvic masses (four cases). Stage IV endometriosis with extensive pelvic involvement was found in two patients. Intraoperatively, the endometriotic lesions involved the ovaries (all cases); Cul de sac (four cases); urinary bladder (two cases); sigmoid colon, hemidiaphragms, and uterine vessels (one case each). The endometriotic lesions were associated with uterine leiomyomas (two patients) and adenocarcinoma of the vagina (one patient). Histologically, in addition to endometrial type glands and stroma, usually found in endometriosis, we observed both cytologic and pattern atypism involving the epithelium in all cases. The features of cytologic atypia included nuclear stratification, hyperchromatism, and pleomorphism. The features of pattern atypia were complex glandular pattern, papillary formations and psammoma bodies. In two cases, these features were sufficient for diagnosis of borderline Mullerian seromucinous tumours. One patient had recurred with metastatic adenocarcinoma of the vault. She died later from disseminated metastatic disease. There is a rare association between pelvic endometriosis and borderline ovarian tumours (three cases), cytologic and pattern atypia (two cases); mesothelial hyperplasia, endosalpingiosis (two cases), and metastasis (one case). Cytologic and pattern atypia can develop in the endometriotic foci and therefore, these lesions should be thoroughly scrutinized for presence of these changes. Our findings recommend surgical excision of these foci rather than their simple cauterization.