The ultrastructure of clear cell adenocarcinoma of endometrium

Abstract

A case of clear cell adenocarcinoma of endometrium was studied by means of light and electron microscopy, and was compared with gestational Arias-Stella cells, as well as with progestin-treated hyperplastic endometrium. The clear appearance of the cytoplasm of the neoplastic cells was due to supra-nuclear pools of glycogen, associated with prominent membranes of granular endoplasmic reticulum. Although Arias-Stella cells did not contain similar ultrastructural features, progestin-treated hyperplastic endometrial cells contained evidence of an increased glycoprotein synthesis. The cytoplasmic organization of the neoplastic endometrial clear cell neoplasms was similar to that previously reported in the ovary, vagina, and cervix, supporting the concept of a common Müllerian, rather than mesonephric, origin for these histologically similar, but spatially separated, neoplasms.