Relation of Leydig Cells in the Human Testicle to the Tubules and Testicular Function

Abstract

GROUPS of Leydig cells have been found in the spermatic cords in 23 of 30 consecutive necropsies. The groups of Leydig cells most commonly occur in the 3 cm. of cord immediately above the upper pole of the testes, but they may be found up to 10 cm. above the globus major, with considerable variation in distribution, both in numbers present and numbers of levels. The cells are constantly distributed in the loose areolar tissue around nerve sheaths and usually infiltrate the nerve bundle, disorganizing the characteristic wavy pattern of nerve fibres. Such cells show all the morphological features characteristic of Leydig cells, crystalloids of Reinke and hyaline bodies occasionally being evident. Infiltration of the nerves by Leydig cells has been described, but not explained, by various authors^1–4. Some thirty years ago this peculiar association occasioned discussion as to the nature of the cells^5,6. The relation to nerves can be accounted for either (a) by migration along nerve fibres at the embryonic period when nerve fibres grow into testicular parenchyma, or (b) by traction of cells from the formed parenchyma during descent of the testicle. The first explanation can be discounted by the similarity of the trabecular pattern of capillaries in normal nerves and the trabecular pattern shown by the infiltrative cells before their continued proliferation disrupts the organized appearance of the nerve.