Ultrastructural changes in the seminiferous tubule wall and intertubular blood vessels in human cryptorchidism.

Biopsy material was obtained from adult men whose both testes had descended into the scrotal sac either spontaneously by use of pharmacologic agents or through surgery at age 7--16 yr, and from undescended testes obtained during orchipexy in men 8--40 yr of age. Testes appeared normal until the 10th yr, when progressive alterations were observed with the onset of puberty and through the adult age both in retained testes and cases of testes that descended through chemical or surgical methods before or after puberty. A thickening of the inner and outer acellular layers of the seminiferous tubule wall was due to an accumulation of collagen fibers and microfibrillar material. The basement membrane was also thickened and appeared as a homogeneous or a multilaminar structure. The intertubular blood vessels presented a thickening of the tunica media and a laminar accumulation of basement-membrane-like material.