Normal endometrial cells in Papanicolaou smears: Prevalence in women with and without endometrial disease

Objective: To determine whether the prevalence of normal endometrial tells in Papanicolaou smears of women with and those without endometrial carcinom a or hyperplasia differs significantly. Methods: Papanicolaou smears of women with biopsy-proved endometrial hyperp lasia or carcinoma diagnosed between 1990 and 1998 were reviewed for the pr esence of normal endometrial cells. Chi-square and a power analysis were us ed to compare these smears with results of smears from women older than 35 years of age with tissue diagnoses other than hyperplasia or carcinoma. All Papanicolaou smears obtained within the 5 years before endometrial samplin g were reviewed. Each patient had at least one smear done within the previo us 12 months. Clinical information was available for all patients. Results: Of the 201 women in whom endometrial hyperplasia (n = 103) or carc inoma (n = 98) was diagnosed, 4 (2%) had normal endometrial cells in otherw ise negative Papanicolaou smears. Of the 289 women in the comparison group, 15 (5%) had normal endometrial cells in their Papanicolaou smears. The pre valence of normal endometrial cells did not differ significantly between th e two groups (P =.071). The study had 80% power to detect a 5% or greater d ifference between groups. Conclusion: The prevalence of normal endometrial cells in Papanicolaou smea rs of women with endometrial carcinoma or hyperplasia does not significantl y differ from that in women without these conditions. Reporting normal endo metrial cells in Papanicolaou smears according to the recommendations of th e Bethesda System may lead to unnecessary procedures and patient anxiety. ( Obstet Gynecol 2000;96: 874-8.) (C) 2000 by The American College of Obstetr icians and Gynecologists.).