A 37-year-old woman with a previous diagnosis of Mayer-Rokitansky-Kuster-Hauser syndrome at 18 years of age was referred from a primary healthcare physician to a gynaecology appointment in our centre. She presented with a 2-year worsening pelvic pain and dyspareunia, symptoms that were previously absent and, at the time, with inadequate relief with oral analgesia. Physical examination showed absent uterine cervix and hypoplastic superior vagina. Transvaginal ultrasound and MRI suggested the presence of an hypoplasic uterus in left rotation. Laparoscopically, two asymmetric rudimentary horns were found, united by a fibrous central band, with an enlarged and congestive left horn. The three structures were removed as a whole. Histopathological examination reported the presence of multiple adenomyotic foci along the full thickness of the left rudimentary horn. The patient had an uneventful postoperative recovery and full remission of her symptoms.