Androgen Treatment in Leydig Cell Proliferation

Patients with the testicular dysgenesis syndrome, that comprises a variable spectrum of clinical manifestations, such as infertility, cryptorchidism, hypospadias, impaired spermatogenesis and testicular germ cell neoplasms, often develop alterations in the Leydig cell compartment. These alterations range from abnormal localization and clustering to hyperplasia or tumorous formation.

Leydig cell tumors (LCTs), although uncommon in the general population, are the most frequent non-germ cell testicular neoplasms, and their incidence has been reported increasingly growing, especially in infertile patients. Given that the focal areas of Leydig cell hyperplasia are nowadays easily detectable at ultrasonography of the testis (US), as small non-palpable hypoechoic micro-nodules that can show internal vascularization, their finding create a diagnostic challenge versus low-stage malignant germ cell tumors.

Patients with testicular dysgenesis syndrome in general exhibit an elevation of Follicle-Stimulating Hormone (FSH), but in these patients, very frequently, even Luteinizing Hormone (LH) is above the reference range. The latter can work as a growth factor for Leydig cells. Since exogenous testosterone can suppress LH levels, it could be that androgen therapy could revert the LH-induced growth stimulation of Leydig cell compartment.

The purpose of this study is to evaluate the effects of androgen therapy on the size and number of non-palpable hypoechoic micro-nodules in patients with elevated gonadotropin levels.

The purpose of this study is also to evaluate whether the behavior (UltraSonographic appearance, US) of the non-palpable hypoechoic micro-nodules during a 4-month trial of testosterone therapy can offer a novel diagnostic tool in the differential diagnosis of benign versus malignant testicular nodules.