The Bethesda System 2001 recommendation for reporting of benign appearing endometrial cells in Pap tests of women age 40 years and older leads to unwarranted surveillance when followed without clinical qualifiers

Objectives.The purpose of this study is to determine the impact of the Bethesda System 2001 recommendation of reporting cytologically benign appearing endometrial cells (BEC) seen in Papanicolaou (Pap) tests of all women age 40 years and older, and to determine the significance of such finding.Methods.Pap tests of women age 40 years and older containing BEC outside of the first half of menstrual cycle reported before and after the Bethesda System 2001 implementation were included. 300 postmenopausal women without BEC were included as control group. Clinical follow-up was reviewed and significant endometrial pathology was defined as simple hyperplasia or a higher diagnosis.Results.BEC reporting rate increased from 0.17% to 0.49% before and after the Bethesda System 2001 (P = 0.0001), due to reporting in women with premenopausal status. Significant endometrial pathology was detected in 14 of 121 (11.6%) postmenopausal patients compared to 7 of 300 (2.3%) in the control group (P = 0.0002, relative risk = 4.96, 95% confidence interval 2.05–11.98), and in none of premenopausal patients. 12 of 14 women with significant endometrial pathology had either postmenopausal bleeding or hormone replacement therapy use.Conclusions.The Bethesda System 2001 led to increased reporting of BEC only in premenopausal women, leading to biopsies performed solely for BEC in these women with no pathology detected. Presence of BEC in Pap tests of postmenopausal women warrants a thorough clinical review, and immediate biopsy is a valid consideration. Presence of hormone therapy or postmenopausal bleeding may be modifiers of risk.