Abnormal cervicovaginal smears due to endometriosis: a continuing problem.

Endometriosis may be challenging when identified on cervicovaginal smears (CVS), leading to an incorrect interpretation of high-grade squamous intraepithelial lesion (HSIL), or atypical glandular cells of undetermined significance (AGUS) including adenocarcinoma in situ (AIS). Awareness of cervical endometriosis, particularly in predisposed patients, is crucial for a correct diagnosis. While cervical endometriosis has been reported to be a diagnostic pitfall of glandular abnormalities, its characteristic features are still not well-established. This may partially be attributed to the varied cytomorphologic features endometriosis shows, depending on menstrual cycle hormonal changes. We describe our experience with three examples where CVS were interpreted as either AGUS or HSIL, which led to a hysterectomy in 2 of 3 patients. Cervical endometriosis needs to be considered with other well-known benign conditions that mimic glandular abnormalities, including cervicitis, tubal metaplasia, lower uterine segment sampling, and microglandular hyperplasia. Published series and our own experience lead us to suggest that these smears will continue to present diagnostic difficulties. Copyright 2002 Wiley-Liss, Inc.