What is Leydig Cell Hyperplasia

Leydig cell

after the Würzburg anatomist Franz von Leydig (1821-1908)
Synonym: Leydig interstitial cell, Leydig interstitial cell
English: Leydig cell

1 definition

The Leydig cells are the most important interstitial cells of the testicle. They make up 10-20% of the organ mass of the testicle.

2 histology

The Leydig cells are large, acidophilic cells. They have a light and rounded nucleus and numerous mitochondria. They lie in groups between the seminiferous tubules (tubuli seminiferi contorti) in the testicular connective tissue, mostly near capillaries.

Intracellularly, Leydig cells have lipid droplets, tubular mitochondria, and plenty of smooth endoplasmic reticulum. This is considered a sign of steroid hormone production. In addition, so-called Reinke crystals made of crystalline protein aggregates can be visible in the cytoplasm. The exact function of these crystals is not yet known (2020), but they are presumably formed as a waste product.

3 function

The most important function of the Leydig cells is testosterone synthesis. The Leydig cells are stimulated by the luteinizing hormone (LH). The testosterone produced by them inhibits the release of LH in the anterior pituitary gland in the sense of a negative feedback.

In addition, Leydig cells also produce paracrine peptides with which they can influence spermatogenesis and blood flow in the area of ​​the seminiferous tubules.

Since the Leydig cells - like Sertoli cells, germ cells, adipocytes and other cell types - can produce the enzyme aromatase, it is possible for them to produce estrogens from androgens.

The functional correlate of Leydig cells in women are the cells of the theca interna of the follicles and the interstitial hilar cells in the medulla ovarii.

4 embryology

Fetal Leydig cells sit in large complexes between the testicular cords. Under the influence of human chorionic gonadotropin (hCG), these cells synthesize androgens from the 8th embryonic week and thus control the differentiation of the male genital tract.

5 clinic

A Leydig cell tumor - and the associated overactivity of the Leydig cells - can lead to increased estrogen production and thus feminization in men. Typical symptoms are then gynecomastia and loss of libido.