[Arteriolar hyalinosis in testicular biopsies (author's transl)].

Arteriolar hyalinosis is a common post mortem finding in the testes of even young men. Identical arteriolar hyalinoses can be demonstrated in testicular biopsies of patients with infertility or in patients operated on for cryptorchidism. In a series of such biopsies from 2400 patients, the frequency of arteriolar hyalinosis was examined. In 7 cases with positive findings, histochemical studies were carried out and in an additional 14 biopsies electron microscopy was performed. Arteriolar hyalinosis was found in 3.75% of the 2,400 patients with disturbances of fertility or cryptorchidism. The mean age of these patients was 34 years. In 58% of the cases with arteriolar hyalinosis the basic testicular lesion was tubular atrophy, in 22% cryptorchidism. The arteriolar lesions were due to deposits of lipoids and mucopolysaccharides. Electron microscopy revealed a granular material with vacuoles and rarely myelin bodies below the endothelial layer and between myocytes and fibrocytes of the arteriolar wall. In later stages elastin-like material could be demonstrated in the vicinity of the endothelial cells and collagen fibers at the periphery of these deposits. The etiology of testicular arteriolar hyalinosis and its pathogenetic significance are not yet clear.