Accessory Cavitated Uterine Mass: A Rare Cause of Severe Dysmenorrhea in Young Women.

We present 3 case reports of a rare Müllerian anomaly called accessory and cavitated uterine mass (ACUM), which is found in young women >30 years of age. They presented with severe dysmenorrhea refractory to medical treatment. The patients were 17, 19, and 25 years old. The patients had the classic Müllerian anomalies. The hysteroscopic examination was normal in all 3 cases, and laparoscopic examination showed a 3- to 4-cm ill-defined mass on the right half of the uterus, without any communication to the uterine cavity. The chocolate-colored material was drained in all of the cases, during excision of the mass. The myometrial defect was sutured laparoscopically. On histological examination, the mass was found to be a cystic cavity, lined by endometrial glands and stroma, which confirmed the diagnosis of ACUM.