Endometrial cells in cervical cytology: review of cytological features and clinical assessment.

The 2001 Bethesda System for Reporting Cervical Cytology recommends reporting benign exfoliated endometrial cells in women age 40 and older, and a review of the literature supports this recommendation. Stromal cells and histiocytes do not need to be reported. The effect of hormonal therapy on endometrial shedding is reviewed. Clinical information should be provided to the laboratory so that appropriate educational notes can be appended to the cytology report. Benign endometrial cells in premenopausal women in the first half of the cycle are not associated with significant pathology and such women do not need additional evaluation. Significant pathology is also unlikely in the second half of the cycle and evaluation may not be required unless clinically indicated. Initial evaluation of other women with benign endometrial cells may include either endometrial sampling or transvaginal ultrasound. Atypical endometrial cells are associated with a higher rate of significant pathology and should lead to additional evaluation. Additional prospective studies on the management of patients with endometrial cells on Pap tests are needed.