[A baby boy with cryptorchism, inguinal hernia and internal female genitalia: the persistent Müllerian duct syndrome].

During operation for a right inguinal hernia, a baby boy aged 3 months was discovered to have internal female genitalia. Biopsies were taken from the gonads and blood was sent for karyotyping. The biopsies showed normal testicular tissue and the karyotyping result was 46XY, so the diagnosis of persistent Müllerian duct syndrome (PMDS) was made. Recovery was uneventful. At the age of 2 he underwent bilateral orchidopexy. PMDS is a rare disorder of the MIF synthesis or receptor. Patients present with cryptorchism, inguinal herniation of Müllerian structures, or problems related to the abnormal urinary tract, such as infection or stone formation. In cryptorchism, orchidopexy and life-long palpatory follow-up are advised. If urological symptoms occur, surgical removal of the Müllerian remnants may be considered. The prognosis for fertility is poor.