Hyperthecosis of the ovary. Clinicopathologic study of 19 cases with immunohistochemical analysis of steroidogenic enzymes.

Nineteen cases of ovarian hyperthecosis found in the Surgical Pathology Department files of the George Washington University Medical Center between 1976 and 1988 were reviewed. In all of these cases the ovaries were removed as part of a procedure for another clinical diagnosis. None of the cases was associated with clinical virilization, but the endometrium was abnormal in 15 of the 17 cases in which it was available for examination, ranging from simple hyperplasia to well differentiated adenocarcinoma. Immunohistochemical analysis of the ovarian lesion for cytochromes P-450 17 alpha and P-450AROM, which catalyze androgen and estrogen synthesis, respectively, was performed in nine cases in which adequate tissue was available. P-450 17 alpha was localized in luteinized stromal cells in six of these cases--the endometrium of four of which was carcinomatous--while P-450AROM was not present in any case. These results confirm androgen production by the luteinized stromal cells in hyperthecosis, and suggests that estrogenic effects in these cases are mediated through peripheral aromatization of these androgens.