[Endocrinology of cryptorchidism]

The testicular descent into the scrotum depends on a series of complex endocrine and mechanical interactions. The first stage or transabdominal that occurs during the first 3 months of gestation is probably produced by the differential growth of the fetus and is believed to be mediated by the Müllerian inhibiting hormone. The second stage or transinguinal migration that occurs during the 8th month of gestation is a complex event depending on the interaction between the hypothalamic-pituitary-testicular hormonal axis and mechanical factors as gubernaculum, intra-abdominal pressure, epididymis. This stage is believed to be androgen dependent. Although hormonal involvement in testicular descent appears clear-cut, there is nevertheless some discrepancy in the literature as to whether cryptorchid children show abnormalities in their hypothalamic-pituitary-testicular axis. Certainly cryptorchidism is a syndrome with various causes. Few cases show primary anatomical abnormalities or are associated to complex congenital anomalies or to clear hormonal defects. Most cases do not recognize an evident cause and an endocrinological abnormality has been suggested. A deficiency in LH and testosterone secretion has been reported in the cryptorchid child.