Endometrial epithelial metaplasias

Abstract

Endometrial epithelial metaplasia refers to the replacement of the normal endometrial glandular epithelium by cells that are not encountered in the normal endometrium or, if present, are usually inconspicuous elements. Because these cells appear unusual or atypical and because they may line architecturally complex glands, this benign process is frequently confused with adenocarcinoma. The clinical and light-microscopic findings in 89 patients with metaplasia of the endometria are presented. Most of these metaplastic changes could be placed in one of the following categories: morules and squamous metaplasia; syncytial papillary metaplasia; ciliated cell metaplasia (tubal metaplasia); eosinophilic metaplasia; mucinous metaplasia; hobnail metaplasia; or clear cell metaplasia. The defining characteristics of each group and their differential diagnoses are discussed. Most women whose endometria demonstrated metaplastic transformation were postmenopausal and most had received some form of oral estrogen replacement therapy within 3 mo. of the time of curettage or endometrial biopsy.