Patients with infertility often presents alterations at ultrasonographic examination of the testis. These alterations include a much higher incidence of small, multiple, non-palpable hypoechoic micro-nodules that can show internal vascularization. This finding often create alarm and anxiety, because it has to be placed in a differential diagnosis versus low-stage malignant germ cell tumors. Nevertheless, explorative surgery reveal that a consistent number of these lesion are benign, due to Leydig cell hyperplasia or Leydig cell tumours. 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.