2025 – PAGE 85 – ENDOCRINOLOGY

AMBIGUOUS GENITALIA

In patients with ambiguous genitalia, ask yourself: Are testes present? Is the penis malformed? Could it be a large clitoris that looks like a penis? Does the meatus look normal?

MICROPENIS

A micropenis is one that LOOKS NORMAL but is < 2 cm in outstretched length. TESTES are present in the scrotum. Look for any signs of possible GROWTH HORMONE DEFICIENCY, PRADER-WILLI, KALLMANN SYNDROME, or PANHYPOPITUITARISM.

ANDROGEN INSENSITIVITY SYNDROME (AKA TESTICULAR FEMINIZATION)

ANDROGEN INSENSITIVITY SYNDROME (AKA testicular feminization) = XY karyotype = X-LINKED RECESSIVE = “teXticular feminization” = Receptor insensitivity to androgens so no male external genitalia develop even though testes are present. Look for a blind ending vagina, lack of uterus, and lack of ovaries in what may appear to be a phenotypic female. Testes may be found in the inguinal canal. This could even present as PRIMARY AMENORRHEA in a phenotypically female person with BREASTS but no pubic hair!

PEARLS: 

• ­If the test mentions a family history of MATERNAL “AUNTS” who are STERILE, they are probably XY TEXTICULAR FEMINIZED UNCLES.
• ­Patients are XY, so MIH IS PRESENT. Therefore, there are NO INTERNAL FEMALE STRUCTURES
• ­Androgens are also present, but the receptors are insensitive. Therefore, the default programming kicks in, and EXTERNAL female genitalia (blind vagina) are formed.
• ­Since patients are not sensitive to androgens, there is NO ADRENARCHE/PUBARCHE. Estrogen receptors work, and some estrogen is present due to conversion from testosterone, so the phenotypical female WILL DEVELOP BREASTS. + Breasts, NO hair, NO menses.