[Undescended testis: aspects of treatment].

Undescended testis (UDT) is the most frequent congenital malformation affecting 1% of 1-year-old mature birth boys. If untreated UDT leads to progressive histological changes with impaired spermatogenesis and an increasing risk of testicular cancer. For clinical reasons palpable testes should be differentiated from impalpable testes. Spontaneous testicular descent can be expected only before 6 months of age. Subsequently, treatment should start without delay and be finished before the child has reached the age of 1 year. Surgery is the cornerstone of treatment. Inguinal approaches are standard practice for palpable testes, whereas laparoscopy is used in non-palpable testes. Hormonal treatment is ineffective for inducing testicular descent but facilitates germ cell maturation and an improvement in fertility potential. Only early treatment of UDT reduces germ cell loss, improves fertility and reduces the risk of testicular cancer.