Testosterone immunoexpression in human Leydig cells of the tunica albuginea testis and spermatic cord. A quantitative study in normal foetuses, young adults, elderly men and patients with cryptorchidism.

A semi-quantitative study of the extra-parenchymal Leydig cells in the tunica albuginea testis and spermatic cord was performed on histological sections immunostained with anti-testosterone antibodies in the testes and spermatic cords obtained from human foetuses, adults and elderly men without testicular or related diseases (autopsy specimens), as well as from adult men with cryptorchidism (surgical specimens). The albugineal Leydig cells appeared in small groups in the vicinity of blood vessels. The Leydig cells of the spermatic cord usually appeared inside or around nerve trunks. The percentages of testes and spermatic cords with extra-parenchymal Leydig cells were higher in the cryptorchid testis group than in the normal male groups. The number of Leydig cells per mm2 in the tunica albuginea testis was higher in normal adult males than in foetuses. This number decreased in elderly men and increased markedly in cryptorchidism. The number of Leydig cells per mm2 in the spermatic cord was also higher in normal adults than in foetuses and it did not change with either advancing age or cryptorchidism. In foetuses, the percentage of cells intensely immunostained by anti-testosterone antibodies in the tunica albuginea and spermatic cord did not differ significantly from that found in the testicular parenchyma, whereas in the other three groups (adult, elderly, and cryptorchid men) the percentages of these cells in the tunica albuginea and spermatic cord were significantly lower than in the testicular parenchyma.