Anorchia is the absence of both
Vanishing testes - anorchia; Empty scrotum - anorchia; Scrotum - empty (anorchia)
Causes, incidence, and risk factors
In the first several weeks after the egg is fertilized, the embryo develops early sex organs. In the male, if the early testes fail to develop before 8 weeks into the pregnancy, the baby will have female genitals.
If the testes are lost between 8 and 10 weeks, the baby will be born with
However, if the testes are lost after the time when the male genitals differentiate (between 12 and 14 weeks), the baby will have normal male genitals (penis and scrotum), but no testes. This is known as congenital anorchia, or the "vanishing testes syndrome."
The cause is unknown, but in some cases there are genetic factors.