Androgen-insensitive male pseudohermaphroditism.

Androgen insensitivity is a mendelian trait transmitted through phenotypically normal females. The affected males exhibit normal fetal testicular development and regression of the müllerian ducts. A luminized uterus is never present. External genitalia are feminine or malformed. The vagina, found in most cases, ends blindly. Female breasts are present in adults. The following three syndromes can be distinguished which differ in the character of the external genitalia: 1) Complete testicular feminization with normal female external genitalia: 2) Incomplete testicular feminization with ambiguous external genitalia showing an enlarged clitoris or phallus; 3) Testicular feminization with hypospadias (androgen-insensitive Reifenstein syndrome). External genitalia are hypospadic, exhibiting scrotal development. The presence of immature Sertoli cells in testicular tubules, in spite of hyperplastic and hypertrophic Leydig cells, is considered to be a pathognomonic histopathologic feature for androgen-insensitivity syndromes. The Leydig cells are able to produce androgens, but androgen-insensitive Sertoli cells are unable to mature.