Pathological survey of intracranial germinoma and pinealoma in Japan.

Pathologic survey was performed on 43 cases of intracranial germinoma and 12 cases of pinealoma. The present study suggests that, in Japan, the incidence of teratoma groups including germinoma is remarkably higher than that in U.S. and Europe, whereas the rate of true pinealoma is lower. Using ultrastructural, enzyme-histochemical, and fluorescence-histochemical methods for a few surgical specimens, a strong similarity between intracranial germinoma (so-called "pinealoma" with a two-cell pattern) and seminoma and dysgerminoma was confirmed. The true pinealoma could be classified as pineoblastoma and pineocytoma, according to the degree of pineocyte differentiation of the tumor cells, and as "neuroblastoma-like" and "pineal-like" on the basis of the histologic architecture.