Disorders of Anti-Mullerian Hormone and Its Receptors: Persistent Mullerian Duct Syndrome

Persistent Mullerian duct syndrome (PMDS), first described by Nilson in 1939, is a rare disorder of internal male sex development. It is considered a very rare disorder and around 300 cases have been published in literature till date. PMDS can be idiopathic or the fallout of an autosomal recessive (85%), X linked or autosomal dominant sex-limited trait. It is estimated that mutation in the anti-Müllerian hormone (AMH) gene on the nineteenth chromosome (type I PMDS, 45%) and an alteration in the AMH receptor (AMHR) gene on the twelfth chromosome (type II PMDS, 40%) are the most common causes. In the remaining cases, the cause is unknown (idiopathic PMDS). Children with PMDS have normal virilized male external genitalia but may have unilateral or bilateral inguinal hernia or cryptorchidism. The Müllerian derivatives are incidentally discovered during the surgery for an inguinal hernia or cryptorchidism. On the basis of pathoanatomy, three types have been described in literature. In the female type PMDS (60–70%), both testes are adherent to the uterus and lie in the ovarian position inside the abdominal cavity. Blind-ending vas and vessels abut the fallopian tube-like structures. The next most common variant, hernia uteri inguinalis (20–30%) is also known as the “male-type” PMDS. It presents as an inguinal hernia with the ipsilateral testis and Mullerian structures as contents of the sac. The contralateral testis is usually found to be undescended on physical examination. The transverse testicular ectopia (TTE) variant is the least common (10%), with both testes and the Müllerian structures descended into one hemiscrotum. The basic principles to be followed in the surgical management of PMDS are (1) Early detection and confirmation of PMDS, (2) Preservation of gonadal function and fertility potential, and (3) Facilitation of testicular self-examination by early orchidopexy. Persistent Mullerian ducts should be excised, or the mucosa should be destroyed completely at the least, to prevent malignant degeneration and recurrent urinary tract infection (UTI). In case it is necessary to leave them in situ, an annual ultrasound is recommended for surveillance to assess any changes in size or a new mass lesion.