Unexpected effect of testosterone in hypergonadotropic hypogonadism and nodular Leydig cell hiperplasia. Report of...

We report a 27 -year-old male referred because of hypergonadotropic hypogonadism with low testosterone and azoospermia. At 23 years of age, he underwent an excision of a hypoechoic 0.7 cm nodule of the left testicle. The pathological diagnosis was a Leydig cell tumor. In the right testicle, there were three nodules at ultrasound, the biggest measuring 0.6 cm. Four years later, the nodules in the right testicle were still present and the larger nodule was excised. The biopsy showed tubules with only Sertoli cells in the perinodular zone. Diffuse and nodular hyperplasia of the Leydig cells was found in the interstitium. The pathological diagnosis was Sertoli syndrome with severe hyperplasia of the Leydig cells. With testosterone therapy, LH decreased, and the nodules disappeared. Thereafter, upon interrupting therapy, LH increased, and the nodules reappeared in two occasions. Resuming testosterone treatment, the nodules disappeared again, suggesting a Leydig cell hyperplasia dependent on chronic LH stimulation.