Endometrial-type cells in cervico-vaginal smears: clinical significance and cytopathologic correlates

This study assessed the significance of endometrial-type cells (ETC) in cervico-vaginal (CV) smears in patients 45 yr and older by evaluating quantitatively and qualitatively the relationship of ETC to subsequent endometrial pathology. In a 3-yr period (1997-1999) at the Johns Hopkins Cytopathology Laboratory, 1,162 CV smears with ETC were found in patients 45 yr and older. In all cases with positive follow-up by tissue biopsy/resection, i.e., endometrial hyperplasia (EHP) and endometrial adenocarcinoma (EACA), the CV smears were reevaluated and compared to the control group (i.e., patients with normal endometrial biopsies). The following cytologic characteristics were recorded: quantity of ETC, type of ETC (epithelial, stromal/histiocyte-type, or mixed), cellular atypism, presence of inflammation, smear background, and associated estrogen effect. Of the 1,162 patients with ETC, 432 cases (37%) had tissue follow-up as follows: EACA, 18 (4.2%); EHP, 20 (4.6%); leiomyomata, 17 (3.9%); endometrial polyp, 21 (4.9%); benign/within normal limits (WNL), 339 (78.5%); nondiagnostic, 17 (3.9%). Cytologic characteristics of ETC showed subtle but definite quantitative and qualitative differences in the major pathologic groups examined. All instances of cancers and hyperplasia occurred in postmenopausal (PM) women. Abnormal vaginal bleeding was the presenting complaint in 66.7% of EACA, 45% of EHP, and 28.6% of benign endometrium. ETC in PM CV smears are associated with significant endometrial lesions (carcinoma, hyperplasia) in less than 9% of the patients. It is concluded that the distinction between EACA and EHP can be difficult. The presence of a large number of ETC, predominantly of epithelial or a mixed (epithelial and stromal) type, is more often associated with EACA or EHP than with benign endometrium. The presence of cytologic atypia and/or diathesis is additionally helpful for the diagnosis of EACA.