Cryptorchidism is the most common congenital condition involving the genital system in boys. The condition is typified by a failure of the testes to descend into the scrotal sac. Thus, at birth, the infants are characterized by the absence of either one (unilateral) or both (bilateral) of the testes from the scrotum. Instead, the testis may be positioned abdominal, inguinal, prescrotal, or gliding (testicle located below the external ring). In most infants diagnosed with cryptorchidism at birth, the testes spontaneously descends into the scrotum by the age of 6 months to a year, although spontaneous descent after a year is very rare. In cases that persist, apart from the psychological complications of such a condition, other complications are lack of fertility, testicular torsion, inguinal hernias, and susceptibility to development of testicular cancer, especially seminomas. Causes and risk factors for this condition include maternal exposure to estrogen during the first trimester, maternal age less than 20-years and more than 35-years, preterm birth, low birth-weight, and twinning.
Almost 3% of infant boys are seen to have cryptorchidism, although by the age of 1-year, only 1% of them continue to be affected. Diagnosis is usually made on the basis of physical examination. The most effective way of managing the condition is by performing infant orchidectomy, a surgical procedure, wherein the testes is brought into the scrotum, and sutured to the scrotal tissue. Occasionally, hormone therapy with human chorionic gonadotropin (hCG) and/or gonadotropin regulating hormone (GnRH) may result in descent of the testes, especially when the testes is situated in the inguinal canal.
Studies indicate mutations in INSL3 gene can cause cryptorchidism. T222P mutation in LGR8 gene has also been known to show a possible association in patients with cryptorchidism.
A study conducted by Abalkhail et al. (2006) to determine the ultrastructural details in the inguinal cryptorchid testes in seven children affected with the unilateral form of the condition, revealed that these changes increase progressively with time. In the younger patients, aged 1, 3, and 5-years, electron microscopic analysis of the testicular tissue showed mainly undifferentiated cells in the seminiferous tubules, with irregular nuclei, thinly marginated heterochromatin, and cytoplasm rich with mitochondria and ribosomes, indicating that the cellular differentiation of the tubules in these young patients was slowed. Other findings were large spermatogonia with few perinuclear mitochondria, primitive sertoli cells with irregular nuclei, and peritubular tissue with collagen, scattered fibroblasts and myoid cells. In contrast, older patients aged between 7 and 13-years, showed tubules with well-differentiated epithelial cells, which had well-marginated heterochromatin at the rim of the nuclear membrane, and cytoplasm filled with vacuoles containing electron dense material. These vacuoles were also noticed in the peritubular tissue. In addition, older children had moderately thickened basement membranes. A 16-year-old affected child showed the maximum number of vacuoles in the cells of the seminiferous tubules and also showed a marked uneven thickening of the basement membrane, along with an increase in number of mast cells in the testes. These findings indicated that irreversible changes to the inguinal cryptorchid testes begin after the age of 5-years.
[Abalkhail A, Banihani I, Al-Baghdadi F, Abu-Ghalyun Y. The morphology of the testicular tissue of unilateral inguinal cryptorchid testes in children: Electron microscopic study. Bahrain Med Bull. 2006; 28(3)]
Sawardekar (2005) determined the prevalence of isolated minor congenital anomalies in 21988 births between 1993 and 2002 using data from the Nizwa Hospital register of congenital anomalies. A total of 25 children with undescended testes were born during this period, giving the condition a prevalence of 1.14 per 1000 births.
Hosani and Czeizel (2000) evaluated the pilot dataset [March-May 1998] of the UAE National Congenital Abnormality Registry (NCAR). A total of 4,861 births were recorded in this study period, with a birth prevalence of total congenital anomalies being 30.3 per 1,000 births. Undescended testes were identified in eight neonates, resulting in an incidence rate of 1.65 per 1,000 births.