All of the following may cause testicular atrophy except :

Torsion testis : It is twisting of spermatic cord which typically results in obstruction of testicular venous drainage while leaving the aeries patent. If untreated this can lead to congestion, hemorrhage and testicular infarction, but this cannot cause atrophy of testis. Main causes of testicular atrophy :- Hypopituitarism Cryptorchidism Irradiation Liver cirrhosis Inflammatory orchitis Antiandrogens prolonged use as in treatment of carcinoma prostate. Persistent stimulation by high levels of the FSH may lead to exhaustion atrophy.