Congenital absence of the testes (Anorchia) is a very rare condition with most paediatric endocrine specialists seeing only two or three boys at any particular time. The boys often present because the parents have noticed that the bag in which the testes sit (the scrotum) is poorly developed or else their attention may be directed to the problem by some other event, for example, the presence of a hernia. It is often during the exploration and repair of a hernia that the problem first comes to light. A number of blood tests are usually conducted at this stage to show that there is no male sex hormone production from the gonad. At the same time a blood sample is often taken to make absolutely sure that the genetic make up of the individual is male.
Although the testes are absent the male external genitalia is otherwise normal. This suggests that there was normal testicular function in early fetal life and normal male differentiation took place. The testes are presumed, therefore, to have regressed for some reason. Torsion of the testes (twisting) in fetal life has been suggested as a cause. No defect in the genes, which regulate male development, has been documented so far in these patients. Ischaemic necrosis (tissue deterioration due to poor blood supply) during descent of the testes is thought to be the more common cause for Anorchia. This occurs during testicular migration when the testis is mobile and vulnerable to torsion.
Boys may also present with rudimentary non-functioning testes, palpable in the scrotum. This is quite a different condition from Anorchia. The importance of making sure that there is no testosterone response to a stimulus is firstly to document that the diagnosis is correct and secondly to make sure that there is no testicular tissue present. Testes may be absent from the scrotum but may be present within the abdomen, which is where they come from in fetal life. It is important to look for a male sex hormone (testosterone) response. If present, the testicular tissue needs to be found because of the potential for development of malignancy within the tissue remnant