Clear-cell adenocarcinoma of the female genital tract.A light and electron microscopic study

We have studied the fine structure of two clear-cell adenocarcinomas of the female genital tract that occurred in postmenopausal women. One arose in the cervix, and the other involved both the endometrium and endocervix and was considered to be of probable endometrial origin. In the first case, both a solid clear-cell pattern and glands lined by hobnail-shaped cells were apparent, while in the second, only the clear-cell pattern was observed. By electron microscopy in both cases, some of the tumor cells contained abundant glycogen granules, and a few cells contained parallel cisternae of granular endoplasmic reticulum. In the first case, acini with luminal surfaces lined by stubby microvilli were present. The tumors were similar in appearance to previously studied clear-cell carcinomas of the female genital tract, and could be distinguished from renal cell carcinoma. Although there was not an exact correspondence, the tumor cells shared a number of features with the cells of gestational glandular hyperplasia of Arias-Stella. The ultrastructural findings, although not conclusive when taken alone, support the body of evidence derived from other sources for the mullerian origin of clear-cell carcinoma of the female genital tract.