My approach to the interpretation of endometrial biopsies and curettings

A major proportion of the workload in many histopathology laboratories is accounted for by endometrial biopsies, either curettage specimens or outpatient biopsy specimens. The increasing use of pipelle and other methods of biopsy not necessitating general anaesthesia has resulted in greater numbers of specimens with scant tissue, resulting in problems in assessing adequacy and in interpreting artefactual changes, some of which appear more common with outpatient biopsies. In this review, the criteria for adequacy and common artefacts in endometrial biopsies, as well as the interpretation of endometrial biopsies in general, are discussed, concentrating on areas that cause problems for pathologists. An adequate clinical history, including knowledge of the age, menstrual history and menopausal status, and information on the use of exogenous hormones and tamoxifen, is necessary for the pathologist to critically evaluate endometrial biopsies. Topics such as endometritis, endometrial polyps, changes that are induced by hormones and tamoxifen within the endometrium, endometrial metaplasias and hyperplasias, atypical polypoid adenomyoma, adenofibroma, adenosarcoma, histological types of endometrial carcinoma and grading of endometrial carcinomas are discussed with regard to endometrial biopsy specimens rather than hysterectomy specimens. The value of ancillary techniques, especially immunohistochemistry, is discussed where appropriate.