Is true hermaphroditism a primary germ cell disorder?

Eleven cases of true hermaphroditism, 6 raised as female and 5 as male, were seen in the 20-year period from 1965 to 1985. External genitalia varied from Prader types II to IV. The ovotestis (11/22) was the most common gonad, and a marked variation in macroscopic and microscopic appearances with five patterns of distribution of gonadal tissue was noted. Ovulation was observed in ovarian tissue, and spermatogonia, but no spermatozoa, in testicular tubules. A hypothesis is developed suggesting abnormal testicular differentiation, and a model is presented to explain observed patterns of gonadal tissue distribution. A uterus was present in all cases, but a hemiuterus or lateralized uterus was noted in the 5 cases in which only testicular or predominantly testicular tissue was observed on the contralateral side. Karyotype analysis showed 46 XX in 5 cases (1 with an H-Y antigen) and a mosaic involving 46 XY in the remaining 5. Spontaneous puberty was achieved in 3 of the females, and of the 4 males with residual testicular tissue, all are prepubertal.