Anorchia is the absence of both testes at birth.

In the first several weeks after fertilization, the embryo develops rudimentary sex organs, which are crucial to the development of internal and external genitalia. In the male, if these early testes fail to develop before 8 weeks gestation, the baby will have female genitalia.

If the testes are lost between 8 and 10 weeks, ambiguous genitalia will be seen at birth. This means that elements of both male and female internal and external genitalia will be seen.

However, if the testes are lost after the critical phase of male differentiation between 12 and 14 weeks, the baby will have normal male internal and external genitalia (penis and scrotum), but the testes will be absent. This is known as congenital anorchia, or the "vanishing testes syndrome."

The specific cause is unknown, but in some cases genetic factors are apparent.

• Normal outside genitalia before puberty
• Failure to enter puberty at expected time and lack of secondary sex characteristics (growth of penis, body and pubic hair growth, deepening of the voice, and increase in muscle mass)

Signs include:

• Empty scrotum
• Lack of secondary sex characteristics

Tests include:

• Testosterone levels (low)
• FSH and LH levels (elevated)
• X,Y karyotype
• Ultrasound or MRI showing absent gonadal tissue
• Bone density (low)
• Anti-Mullerian hormone levels (low)
• Surgical exploration to search for evidence of male gonadal tissue

Treatment includes androgen (male hormone) supplementation, testicular prosthetic implantation, and psychological support.

Prognosis is good with treatment.

Complications include infertility, psychological problems related to gender, and occasional face, neck, or back abnormalities.

Call your health care provider if your male child appears to have extremely small or absent testicles or does not appear to be entering puberty during his early teens.