True hermaphroditism is a rare cause of genital ambiguity characterized by the presence of ovarian and testicular tissue in an individual, leading to development of both male and female structures. At least 500 patients have been reported. Most of them show evidence of ambiguous genitalia at birth, but the phenotype of external genitalia may range from normal male to normal female, depending on the degree of testicular tissue present. Ambiguous external genitalia may include hypospadias, genital bud, urogenital sinus, labioscrotal folds and hemiscrotum. Gonads are most frequently ovotestes (containing both ovarian and testicular tissues), but any pattern of ovary, testis, or ovotestis is possible. They may be situated in an abdominal, inguinal or labioscrotal position. Development of internal genitalia is variable, usually corresponding to the adjacent gonad. Abnormal vagina is often present, ending in the urogenital sinus. The uterus, if present, is usually hypoplastic. At puberty, breast development, signs of feminization and menstruation may occur. Sterility is frequent, although ovulation and spermatogenesis are possible. Basal and stimulated testosterone and estrogen levels confirm the presence of functional ovarian and testicular tissues, respectively. True hermaphroditism is a genetically heterogeneous condition. Most patients have a 46,XX karyotype (60%); 46XX/46XY mosaicism, 46,XY karyotype or X-Y translocation are less frequent. Management of true hermaphrodites must be carefully discussed. If detected at birth, gender assignment depends on the appearance of the external genitalia and gonad histology. Removal of all contradictory gonadal tissue and appropriate hormonal substitution should be performed to allow gender-specific development. Undescended and dysmorphic testicular tissue should be removed, because of the increased risk of malignant gonadal tumors.
Last update: February 2005