How often are endometrial polyps malignant in asymptomatic postmenopausal women? A multicenter study.

OBJECTIVE: The objective of the study was to evaluate the prevalence of cancer and premalignant lesions in polyps on atrophic endometrium in asymptomatic postmenopausal women to compare these findings with a similar cohort of patients with abnormal uterine bleeding.
STUDY DESIGN: One thousand one hundred fifty-two asymptomatic and 770 consecutive postmenopausal women with abnormal uterine bleeding were included in a retrospective multicenter study. Recruited patients underwent hysteroscopic polypectomy based on a sonohysterographic or hysteroscopic diagnosis. The pathologic report was the main outcome measure.
RESULTS: One single case of stage 1 grade 1 endometrial carcinoma on a polyp with a mean diameter of 40 mm (0.1%) was observed in asymptomatic women. This prevalence was 10 times lower than in symptomatic patients (P < .0001). The prevalence of atypical hyperplastic polyps was 1.2% in asymptomatic women (2.2% in symptomatic patients; P < .005). At multivariate analysis, polyps' diameter was the only variable significantly associated to an abnormal histology (cancer, polypoid cancer, and atypical hyperplasia) in asymptomatic women (odds ratio for polyps with mean diameter > 18 mm, 6.9; confidence interval, 2.2-21.4).
CONCLUSION: Follow-up and/or treatment of endometrial polyps incidentally diagnosed in asymptomatic postmenopausal patients could be safely restricted to few selected cases based on polyp diameter.