Diffuse intratubular undifferentiated germ cell tumor in both testes of a male subject with a uterus and ipsilateral testicular dysgenesis.

A case of müllerian pseudohermaphroditism in a male subject with a uterus is described. The patient showed normal secondary sex characteristics as well as normal external genitalia, except for right cryptorchidism and a painful tumoral mass in the left testis. Examination of surgical specimens revealed a uterus attached to the left ductus deferens. Areas of seminoma and embryonal carcinoma were present in the left testis. In addition, there was a thin insufficiently collagenized albuginea that contained a cellular connective tissue resembling the ovarian stroma, as well as hypoplastic and atrophic seminiferous tubules. In the testicular parenchyma most of the seminiferous tubules located far away from the tumor possessed the atypical malignant germ cells characteristic of intratubular undifferentiated germ cell tumors. No spermatogenesis was seen. The right abdominal testis was atrophic and showed a normal albuginea. However, there was an undifferentiated germ cell tumor similar to that observed in the left testis. We describe the first case of a tumor in a scrotal testis of a male subject with a uterus. The occurrence of this tumor is discussed with regard to tubular dysgenesis present in both testes and supported by the intrinsically abnormal germ cells as well as by the immature Sertoli cells found in both testes.