anorchie

Anorchie, also referred to as anorchism or bilateral testicular agenesis, is the congenital absence of both testes. It is a rare form of gonadal agenesis. Most cases are identified in infancy or early childhood due to non-palpable testes in a male newborn, though the phenotype can vary from apparent male to female or ambiguous depending on hormonal influences during development.

Pathophysiology and presentation: Anorchia results from failure of testicular tissue to develop or from regression of early testicular primordia during fetal life. The absence of testes eliminates the production of testosterone and anti-Müllerian hormone, which can lead to reduced masculinization in utero. In 46,XY individuals, this can result in a spectrum from a primarily female-appearing external genitalia with a uterus and upper vagina to atypical or ambiguous genitalia. In many cases, individuals present with non-palpable testes or with signs of gonadal failure at puberty, depending on the degree of androgen exposure and tissue remnants.

Diagnosis: The diagnosis is suspected when both testes are not palpable and imaging (ultrasound or MRI) does not reveal testicular tissue. A karyotype is often performed and may show 46,XY. Hormonal testing typically shows very low testosterone levels, and gonadotropin levels may be elevated due to loss of negative feedback. Endocrine and anatomical findings guide decisions about sex assignment and management.

Management and prognosis: Treatment is multidisciplinary and individualized, focusing on hormone replacement therapy appropriate to the chosen gender identity (estrogen for those raised as female, or testosterone for those raised as male) to induce and sustain secondary sexual characteristics. Fertility is not possible due to absence of testes. Psychological support and long-term medical follow-up are important. Early counseling regarding geography of anatomy, puberty, and potential gynecological considerations is advised.

See also: gonadal agenesis, vanishing testis syndrome, testicular agenesis, primary hypogonadism.