[Contribution to the formal pathogenesis of the classical seminoma. Early diagnosis from testicular biopsies?]

13 cases of seminoma of the testes were investigated in detail by means of light microscopy using paraffin and semithin sections. Paraffin sections were the basis for diagnosis, therapy, and prognosis. In semithin sectins, even individual seminoma cells within the seminiferous tubules were recognized by characteristic cytological features. In semithin sections also the development of the solid tumor from intratubular seminoma cells was elucidated. On the basis of our findings, the following concept of seminoma spread may be advanced: intratubular seminoma cells invade the lamina propria and gain access to to the interstitial tissue. Subsequent to the migration of seminoma cells, the tubules are smaller in diameter and contain only Sertoli cells. The seminoma cells in the interstitial tissue increase in number and build up the solid tumor.