Intramyometrial mature cystic teratoma in a Rudimentary horn in Mayer-Rokitansky-Küster-Hauser (MRKH) Syndrome: A Rare Surgical Finding.

Extragonadal dermoids are extremely rare, reported in 0.4% of all ovarian teratomas. Here we report a case of mature cystic teratoma in the rudimentary horn in an 18-year-old patient with Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome who presented with primary amenorrhea, intermittent abdominal pain and difficulty during sexual intercourse. Magnetic resonance imaging demonstrated bilateral rudimentary uterine horns with intraluminal blood in the left horn. The patient underwent laparoscopic Davydov peritoneal pull-through vaginoplasty with excision of the left rudimentary uterine horn. Histopathological examination revealed an unexpected intramyometrial mature cystic teratoma within the anterior wall of the excised uterine horn. Retrospective MRI review identified a previously overlooked subtle T2- hypointense lesion corresponding to the location of mature cystic teratoma. To the best of our knowledge, this is the first reported case of mature cystic teratoma in a rudimentary horn of uterus in a patient with MRKH in the literature.