Quantitative histology of germ cells in the undescended testes of human fetuses, neonates and infants.

Abstract

We investigated the number of germ cells per tubular cross section and testicular weight in cryptorchid fetuses, neonates and infants, and characterized additional abnormalities. Our series comprised 35 fetuses and 58 boys with cryptorchidism, and 22 normal fetuses and 25 normal boys. Age ranged from 28 weeks of gestation to 3 years. Cryptorchid fetuses had reduced germ cells per tubular cross section values and lower testicular weights. Values were reduced in cryptorchid boys without a symptomatic inguinal hernia. If a hernia was present, values were normal in the first year of life but decreased at age 1 to 3 years. Malformations or dysplasia of the kidneys, ureter or T10 to S5 vertebrae were present in 34% of the cryptorchid fetuses and 18% of the cryptorchid boys without a symptomatic inguinal hernia. Our study suggests a reduced number of germ cells in undescended testes from week 28 of gestation and germ cell hypoplasia as a consequence of continued postnatal undescended testicular position. Cryptorchidism may result from abnormal development of the caudal developmental field.