[Endocrine interrelationships in patients with malignant testicular tumours (author's transl)].

Testicular function was investigated in 40 patients with malignant testicular tumours of different histology and tumour stage, by spermatological and endocrinological analyses. In patients without ectopic production of beta-HCG in the tumour tissue a hypergonadotropic tubular disfunction of the testis was present, resulting in elevated plasma FSH concentrations and moderate to severe oligozoospermia. Ectopic production of beta-HCG in the tumour stimulates the secretion of 17 beta-oestradiol, particularly in the Leydig cells, which suppresses pituitary gonadotropin secretion via negative testicular pituitary feedback. Spermatological analyses showed severe spermatogenetic disorders. Prolactin levels, however, were not altered in patients with testicular cancer.