Is testosterone involved in the initiation of spermatogenesis in humans? A clinicopathological presentation and physiological considerations in four patients with Leydig cell tumours of the testis or secondary Leydig cell hyperplasia

Abstract
The purpose of this study was to evaluate the role of testosterone on the puberal development of spermatogenesis and to present additional clinicopathological data which bring about new information to this controversial subject. Four pre‐pubertal patients are presented, 2 of them bearing Leydig cell tumours of the testis in the form of nodular masses. In both cases seminiferous tubules in the immediate vecinity to the tumours showed complete development of spermatogenesis, while those located away from the tumours were infantile in nature. Gonadotrophic levels were within the normal pre‐pubertal range in these 2 cases. In one of the patients, testosterone concentration in the testis showed higher values than normal, and a concentration gradient was detected between the tumoral nodule and non‐tumoral parenchyma. The 3rd patient had a pineal choriocarcinoma producing high amounts of hCG and consequently a diffuse hyperplasia of Leydig cells with high levels of plasma testosterone. Seminiferous tubules showed development up to pachytene spermatocytes. The last case was a precocious puberty in a boy with a tumour of the 3rd ventricle area. He had elevated levels of testosterone in the testis and plasma. In the testicular biopsy, stimulation of Leydig cells was detected. The seminiferous tubules showed mature Sertoli cells and pachytene spermatocytes. FSH levels were abnormally low. These 4 cases present in common different situations in which abnormally high amounts of testos‐happens in the immature rat, the interaction between testosterone and gonadotrophins is essential for the normal initiation of spermatogenesis in normal puberty. Considerations are discussed on the possible synergistic role of gonadotrophins or other factors in relation with stimulation of seminiferous tubules by testosterone.