Endometrial hyperplasia involving endometrial polyps: report of a series and discussion of the significance in an endometrial biopsy specimen

Objectives  Endometrial polyps are a common cause of abnormal uterine bleeding. Rarely, a hyperplasia, either complex or atypical in type, is identified within a polyp in a biopsy or polypectomy specimen. Currently, it is not known whether the hyperplasia is likely to be confined to the polyp or also involve nonpolypoid endometrium. We aim to assess the likelihood of hyperplasia being confined to an endometrial polyp.
Design  In this study, we identified 32 women from pathology archives in whom endometrial hyperplasia was present within a polyp. The number of endometrial polyps during the study period was 1031 and therefore 3.1% of all endometrial polyps diagnosed during the study period contained a hyperplasia.
Setting  A major teaching hospital in the UK.
Methods  The biopsies were retrieved from the pathology archives of Royal Group of Hospitals, Belfast, between 2000 and 2006. We traced any follow-up biopsy or hysterectomy specimens to evaluate the status of the surrounding endometrium.
Results  The hyperplasias were complex ( n = 23) or atypical ( n = 9) in type. In 14 of 27 (52%) women in whom nonpolypoid endometrium was available for histological evaluation, either on the original biopsy or in a follow-up specimen, hyperplasia involved the nonpolypoid endometrium, and in three other women, hyperplasia was present in a polyp in follow-up specimens. Women with atypical hyperplasia in a polyp were slightly more likely to have hyperplasia in the surrounding endometrium than those with complex hyperplasia.
Conclusions  Our study illustrates that the risk of endometrial hyperplasia in a polyp concurrently involving nonpolypoid endometrium is significant. We suggest a strategy for the management of women with hyperplasia identified within an endometrial polyp in a biopsy or polypectomy specimen.