ELECTRON MICROSCOPIC STUDIES ON HISTOGENESIS OF TESTICULAR TUMOR

1. Electron Microscopic Observations of Spermatocytic Seminoma

Abstract

A case of spermatocytic seminoma was examined by electron microscopy. Tumor cell size was variable but medium-sized cells dominated. These cells showed several important features as follows: round to oval nuclei with regular margin; prominent nucleoli with dispersed nucleolonema; finely scattered chromatin and occasionally with condensed chromatin in most nuclei; true intercellular bridge, almost identical to those normally seen between germ cells; tubular invagination of nuclear envelope identical to those of typical seminoma; specialized cell junctions of the macula adherens; basal bodies and striated ciliary rootlets.
Compared with a typical seminoma, they have a close resemblance in nuclear aspects, but a true intercellular bridge seems to be peculiar to spermatocytic seminoma.
These ultrastructural findings suggest a germ cell origin of this tumor, but to disclose its more exact origin, i. e., germ cell type, further examination will be needed.