Ovarian dysgerminoma: an ultrastructural study.

A case of ovarian dysgerminoma, found in a 14-year-old girl, is described. The ultrastructural study showed three different types of cells-two kinds of tumor cells(the main tumor cells of the germ-cell type and the second type with deeply indented nuclei and scanty cytoplasm) and stromal cells. The tumor also showed a typical lymphocytic infiltration, and the cells appeared to be embedded in a matrix of collagen fibers and ground substance.