Testicular descent is a complex multistep embryonic process that requires the interaction between anatomical, hormonal and genetic factors. Failure of any of these steps results in cryptorchidism and other testicular abnormalities as testicular
ectopia, retractile testis, anorchia, atrophic testis or associated conditions as hypospadias and inguinal hernia (Perlin et al., 2003). Also, crytorchidism is associated with a 3 - 5% incidence of renal anomalies (Sadler et al., 1995).
Cryptorchidism is the most frequent congenital anomaly of the urogenital tract in human males affecting I - 3% of newborn boys (Moore and Persaud, 2003). Cryptorchidism is defined as failure of the testis to descend from its abdominal location into the scrotum. In one third of the patients, the condition is bilateral. Cryptorchid testis is 20 - 48 times more likely to undergo malignancy than normal testis. Orchipexy is the treatment of choice and usually performed in patients aged 2 - 10 years except if there is an association with inguinal hernia, in which case the operation can be performed very soon after the diagnosis is confirmed (Moore and Persaud, 2003). It is better to avoid intervention before the age of one year in cases not associated with inguinal hernias as the possibility of spontaneous test..ular descent is common (Dogra and Mojibian, 2003). The mechanism that regulates testicular migration is not yet well established.
The most accepted theories for explaining testicular migration arc related to increased intra-abdominal pressure, the development of the epididymis, vas deferens, inguinal canal. development of gubernaculum, stimulus from the genitofemoral nerve (which innervates testicular gubernaculum), various hormonal stimuli mainly  testosterone.enti-mullerian hormone (AMH), insulin-like factor (InsL 3) and relaxin in addition to biologically active peptides with systemic and / or paracrine effects (Kubota et at, 2001 & 2002; Vigueras et at, 2003).