[Ultrastructure and histogenesis of spermatocytic seminoma].

Electron microscope study of spermatocytic seminoma revealed cells at various stages of differentiation. The generally high level of cell differentiation suggested the advancement of the process in the said neoplasms. A comparative study of normal spermatogenic epithelium and spermatocytic seminoma showed a resemblance of tumor cell differentiation and spermatogenic epithelium development. These common features included filament structure formation, characteristic of primary spermatocyte at leptonema stage of meiosis, formation of ponticuli intercellulares and the increased level of complex lamellosus elements. Spermatocytic seminoma seems to result from malignant transformation of progenitor cells-spermatogonii B. This accounts for the high degree of specific cell differentiation of tumor, as compared with standard seminoma.