Cryptorchidism: its influence on male fertility and the risk of the testicular tumor

Abstract

In the embryonic stage, the testes develop in the abdomen and descend to scrotum, just before or at birth. The undescended testis is the result of the arrest of descent of testis in some part along its path, to the scrotum. The bilateral undescended testis is called Cryptorchidism which means hidden testis. The factors that contribute to the descent of testis includes Gubernaculum testis, the differential growth of abdominal wall, intra-abdominal pressure and temperature, Calcitonin gene-related peptide (CGRP), male sex hormones, insulin-like hormone 3 (INSL3) and maternal gonadotrophins. The descent of testis may become erratic and gives rise to undescended testis, ectopic testis, congenital hernia, and hydrocoele etc. As a rough estimate approximately 2-4% of male infants are born with Cryptorchism, thus making it, one of the most common congenital anomalies, in the male genitalia. It was found that the incidence of azoospermia in unilateral cryptorchidism was 13%, but in untreated bilateral cryptorchidism, it reaches up to 89%. Cryptorchid boys have increased the risk of a testicular tumor, mainly seminoma. Persistent exposure to high temperature in cryptorchidism could allow maturation of the neonatal gonocytes that has failed to mature as spermatogonia or undergo apoptosis. These cells may persist in testes for years together and eventually become carcinoma in situ cells with a high risk of testicular malignancy later in life i.e., 20-40 years of age. This review addresses the cryptorchidism, its influence on fertility and the risk of developing testicular germ cell tumor. The hormonal factors involved in testicular descend or otherwise is also highlighted.