Positive predictive value of endometrial polyps in Pipelle aspiration sampling: a histopathological study of 195 cases.

Objective: To estimate the positive predictive value of Pipelle endometrial sampling in detecting the presence of an underlying endometrial polyp. The secondary objective is to examine the histologic features that can predict the presence of endometrial polyps.

Study Design: This is a retrospective case review study. 195 women who had undergone diagnostic hysteroscopy and/or polypectomy were identified in a University teaching hospital. All patients had a prior polyp diagnosis in the Pipelle endometrial sample. The histology of these samples were compared and analyzed with subsequent DH findings and final hysteroscopic biopsies. Slides were reviewed by 2 gynaecological pathologists.

Results: 162 women were premenopausal (mean age 46.1, SD=4.6) and 33 were postmenopausal (mean age 57.2, SD=8.1). The commonest indication for a Pipelle endometrial sampling was abnormal uterine bleeding. Presence of polyp was confirmed by DH in 56.3% (111/195) cases. Of these, 81.1% (90/111) were confirmed histologically. The positive predictive value of detection of polyps in Pipelle endometrial samples for premenopausal and postmenopausal women was 53.7% and 72.7%, respectively (p=.05). The most reliable histologic features that can predict the presence of an underlying polyp was fibrous stroma (p=.01) and focal glandular clustering (p=.03). The prevalence of endometrial hyperplasia and carcinoma in women who was confirmed to have polyp was 11.7% (13/111).

Conclusion: The positive predictive value of Pipelle endometrial samples in detecting endometrial polyps was 56.3%. It was higher in the postmenopausal women (72.7%) compared to premenopausal women (53.7%). The prevalence of endometrial hyperplasia and carcinoma in women who was confirmed to have polyp was consistent with the rate reported in the literature. Using ultrasonography as an adjunct maybe helpful in diagnosing endometrial polyps.