The undescended testicle.

Cryptorchidism results from a complex hereditary series of incompletely understood events involving the HPG axis. The incidence is indirectly related to birth weight and dramatically decreases during the first 3 months after birth. Many nonscrotal testes are retractile and require no therapy whatsoever. True cryptorchid testes develop identifiable histologic alterations within 2 years of parturition, and endocrine abnormalities are often detectable during infancy. Hormonal therapy with hCG is effective in causing descent in only a small percent of children with cryptorchidism. GnRH nasal spray is no different from placebo in double-blind studies in which retractile testes have been excluded. The results are best in low-lying testes and in older children, but a recognized late-failure rate requires continued surveillance. HCG therapy appears to be of little use in nonpalpable cryptorchid testes. The risk of testicular cancer is increased in men with a history of cryptorchidism and even includes the contralateral descended testes. This risk may be reduced by early orchidopexy. Fertility is impaired in men with cryptorchidism and is reported to be no better than 75% and 50%, respectively, in men who have undergone successful unilateral or bilateral orchidopexy. There is unconfirmed evidence that orchidopexy carried out before the age of 2 years may improve these fertility rates. It is recommended that all children with cryptorchid testes undergo treatment by the age of 1 or 2 years. The parents of children with a nonpalpable testis should be informed of the high rate of testicular absence. If hormonal therapy is to be used, it must be initiated at 10 months of age. Treatment failures must be identified quickly to allow prompt referral of these children to a pediatric urologist or surgeon for orchidopexy.