Ovarian granulosa cell tumors--immunohistochemical localization of estradiol and ultrastructure, with functional correlations.

The authors studied immunohistochemical localization of estradiol and ultrastructure in 11 ovarian granulosa cell tumors in an effort to establish the cellular source of increased estrogen in patients with granulosa cell tumors. Estradiol was identified by the immunoperoxidase method in 10 tumors, and staining was confined to scattered groups of granulosa cells or isolated granulosa cells. The majority of tumor cells in all 5 cases examined by electron microscopy were undifferentiated cells, but in 2 cases, a small percentage of tumor cells contained mitochondria with tubular cristae and well-developed smooth endoplasmic reticulum. Interpreted in conjunction with in vitro studies of granulosa cells, the results suggest that neoplastic granulosa cells may resemble ovarian follicular granulosa cells of all stages of maturation and are capable of estrogen production.