The Brenner tumor: a report of multiple tumors.

A case of multiple Brenner tumors was studied with light and electron microscopy. Among the epithelial elements, argyrophil cells were found in addition to the typical "transitional" and mucus-secreting cells. In some areas, it was not possible to distinguish epithelial from tumor stromal cells. By electron microscopy, dense-core secretory granules were identified, as well as previously undescribed cytoplasmic tubular bodies. Some epithelial cells were intimately associated with reticulin and collagen. Some stromal cells had desmosomes, dense bodies, incomplete basal lamina, and, occasionally, multivesicular bodies, which suggests epithelial differentiation. Previous authors have documented morphologic similarities and continuity between Brenner-tumor epithelium and ovarian cells of almost every type. The inference is that there are multiple possible sources for the Brenner tumor. Classification must therefore be based on realize differentiation rather than presumed cell of origin.