Mucinous Epithelial Lesions in Endometrial Curettage Material

Abstract

To evaluate the immunohistochemical expression of several benign or malignant mucinous lesions that can be encountered in endometrial curettage material. Nineteen well-differentiated mucinous endometrial carcinomas, 12 papillary mucinous metaplasias, 11 cervical microglandular hyperplasias, 11 endocervical adenocarcinomas, 2 goblet cell metaplasias, 1 minimal-deviation adenocarcinoma, and 1 lobular endocervical glandular hyperplasia entered the study. Immunohistochemistry was performed with the following antibodies against: estrogen receptors, progesterone receptors, vimentin, p16, p63, carcinoembryonic antigen, and Ki-67. Immunohistochemistry could easily distinguish endocervical adenocarcinoma of usual type from all other lesions under study. A Vim(-)/p16(-)/p63(high) signature was found to favor a cervical microglandular hyperplasia, whereas both mucinous endometrial carcinoma and mucinous papillary metaplasia would be preferentially characterized by a Vim(+)/p16(+)/p63(low) immunophenotype. A high Ki-67 expression would be of help in differentiating the latter 2 conditions. Statistically, the expression of estrogen receptors, progesterone receptors, and carcinoembryonic antigen did not aid in the differential diagnosis of these 3 conditions. For the 4 cases representing goblet cell metaplasia, minimal-deviation adenocarcinoma and lobular endocervical glandular hyperplasia, no results could be drawn. In endometrial curettage material, the differential diagnosis of lesions comprising mucinous epithelium might be rendered by combining the immunohistochemical expression of vimentin, p16, p63, and Ki-67. Of all lesions, endocervical adenocarcinoma of usual type is the most easily identified.