Functional pathology of human ovarian steroidogenesis: Normal cycling ovary and steroid-producing neoplasms.

In human reproductive endocrinology and pathology, it is important to localize the sites of steroid hormone production to obtain a better understanding of steroid metabolism. Previous approaches, including morphological and biological studies, could not sufficiently demonstrate which cells produce what steroids in both normal and pathological human ovaries. Recent development of immunohistochemistry and in situ hybridization of the enzymes specifically involved in sex steroid biosynthesis made it possible to detect the expression of steroidogenic enzymes, and subsequently the sites of specific steroid production in diagnostic pathology materials. There are, however, some limitations in the approaches, including correlation of the findings with preoperative systemic hormonal manifestations in the patients with sex cord-stromal tumors of the ovary, and great care should be taken when interpreting results.