Atypical endometrial polyps and the incidence of endometrial cancer: a retrospective cohort study

Objective The aim of this study was to evaluate the incidence of endometrial carcinoma, proven after hysterectomy, in patients diagnosed with atypical endometrial hyperplasia confined to a polyp. A secondary aim was to establish factors associated with (pre‐)malignant alterations in a polyp. Design A retrospective cohort study. Setting Maastricht University Medical Centre (MUMC+) and Máxima Medical Centre in Eindhoven/Veldhoven (Máxima MC). Population Women who underwent a hysteroscopic polyp resection between 2008 and 2016. Methods Patient characteristics and histopathology results of the polyp and, in the case of a hysterectomy, uterus were collected from patients’ charts. Results A total of 1445 complete hysteroscopic polyp resections were included. Of those, 1390 polyps showed benign histopathology results, 39 polyps contained atypical hyperplasia and 16 polyps contained endometrial carcinoma. A hysterectomy was performed in 35 women who were diagnosed with atypical hyperplasia confined to a polyp after hysteroscopic polyp resection. Histopathological assessment showed no additional (pre‐)malignant changes of the endometrium in 12 women (30.8%), atypical hyperplasia in 11 women (28.2%) and endometrial carcinoma in 12 women (30.8%). None of the prognostic factors under consideration were significantly associated with (pre‐)malignant changes in a polyp. Conclusion The incidence of endometrial carcinoma in the surrounding endometrium after complete resection of a polyp with atypical hyperplasia is 30.8% in this study. This supports the current advice to perform a hysterectomy and bilateral salpingo‐oophorectomy. No prognostic factor for (pre‐)malignant changes in a polyp was established. Tweetable abstract The incidence of endometrial carcinoma after complete resection of a polyp with atypical hyperplasia is high.