The undescended testis: diagnosis, treatment and long-term consequences.

BACKGROUND: The late descent of a testicle into the scrotum may impair its development. Reduced fertility is the main risk of primary cryptorchidism even after timely treatment, as histopathological changes (Leydig cell hypoplasia) already become apparent in the first few months of life. There is evidence, however, that treatment is often delayed. Hormonal and surgical treatments complement each other and should be provided before the child's first birthday. METHODS: Selective literature search in PubMed (January 2008) based on the following keywords: "cryptorchidism", "maldescensus testis", "etiology", "therapy", "semen quality", "testicular cancer". Particular attention was paid to the current S2 guidelines on cryptorchidism. RESULTS/DISCUSSION: Hormone therapy is the best initial treatment in most cases, with a few exceptions. If this is unsuccessful, surgery should be performed without delay. The success of treatment depends on the initial position of the testicle. Treatment does not lessen the risk of malignancy. Parents must be informed about this risk. The undescended testicle is the most common genital malformation in boys. When diagnosed, it should be treated hormonally and/or surgically before the child's first birthday to minimize the risk of impaired fertility. Successful treatment before age 13 appears not to lessen the risk of testicular cancer, but it does facilitate early detection by enabling physical examination of the testicle.