Endometrioid carcinoma of the ovary. A clinicopathologic, histochemical, and electron microscopic study.

A material consisting of 23 endometrioid ovarian carcinomas, including 2 rare endometrioid tumors with argyrophil cells, was analyzed clinically and with the use of various histochemical staining methods. Electron microscopy was performed in 3 cases. Apical neutral mucin mixed with sulfate and carboxyl groups was typical for the cells at the light microscopic level, and a prominent Golgi complex with many small secretory vesicles was commonly seen at the ultrastructural level. The nuclei had concentric nuclear bodies and nucleoli with mesh-basket appearance. There was a positive correlation between the grade of differentiation and clinical stage. The corrected 5-year survival rate was 80% in stage I, 50% in stage II, 17% in stage III, and 0% in stage IV; the overall 5-year survival rate was 46%. Signs of increased endometrial estrogen activity were found in 6 of the 12 postmenopausal patients. In the whole series, 6 endometrial carcinomas were found simultaneously with the ovarian carcinoma.