[Hypogonadism despite of normal testosterone levels].

We report on a 19 year old patient with clinical signs of hypogonadism (small testicles, missing pollutions and diminished beard growth) despite of normal testosterone levels. Further diagnostic procedures revealed panhypopituitarism with insufficiency of the gonadotrope, somatotrope and corticotrope axis due to a beta-HCG-producing suprasellar germinoma with intracerebral metastases. Paraneoplastic production of beta-HCG resulted in sufficient stimulation of Leydig cells with normal production of testosterone, which had partly masked clinical symptoms of gonatrope insufficiency. The patient was treated by combined radiochemotherapy and is in remission since 7 years.