Accessory cavitated uterine malformation: Enhancing awareness about this unexplored perpetrator of dysmenorrhea.

An accessory cavitated uterine mass (or malformation) (ACUM) is an isolated cystic uterine lesion located at the lateral aspect of the myometrium just below the insertion of the round ligament. Often the source of severe dysmenorrhea and pelvic pain, this condition is classified as a Müllerian abnormality. Understanding ACUMs, recognizing their clinical appearance, diagnosing an ACUM with ultrasound or magnetic resonance imaging, and advising patients about conservative, medicinal, and surgical treatment options is important to all clinicians. Although ACUM primarily presents with severe dysmenorrhea but can have other clinical symptoms, we have provided a few sample cases to help clinicians prepare for ACUM encounters. We also reviewed the other published literature available on ACUM regarding clinical presentation, etiology, and management. Last but not least, based on our research and the work of others, we offer a set of characteristics that will be useful in diagnosing and treating ACUM. ACUM diagnosis is crucial in clinically suspicious circumstances, and early treatment significantly enhances patients' quality of life.