An ultrastructural study on germinoma cells.

Germinoma cells were ultrastructurally studied in 17 cases composed of 8 cases with testicular seminoma, 3 cases with ovarian dysgerminoma, 4 cases with intracranial germinoma and one case with mediastinal germinoma. The tumor cells were generally polyhedral in shape, and has frequently a cytoplasmic process, occasionally a long process like a pseudopod. Regarding several components of the cytoplasm, most of the tumor cells in all but few cases had varying numbers of glycogen granules and fatty droplets, some of tumor cells in all but few cases had annulate lamellae, junctional apparatuses and microvilli, while stacks of rER or large autolysomes were observed in some of the tumor cells in several cases. In some of the seminoma cells and dysgerminoma cells observed were one or more of 4 types of intranuclear pseudoinclusions. Definite differences among germinoma cells associated with their originating sites were not recognized except for a few features of the nucleus.