Accessory cavitated uterine malformation: A rare and often misdiagnosed müllerian anomaly- A case report

Accessory cavitated uterine malformation (ACUM) is a rare Müllerian anomaly characterized by a non-communicating, endometrium-lined cavitated lesion within an otherwise normal uterus. It typically presents with severe dysmenorrhoea and chronic pelvic pain in young women and is frequently misdiagnosed. A 26-year-old woman presented with progressively worsening dysmenorrhoea and chronic pelvic pain since menarche, with otherwise normal menstrual cycles. Ultrasonography revealed a solid-cystic lesion adjacent to the uterus. Magnetic resonance imaging demonstrated a well-defined, thick-walled cavitated lesion with hemorrhagic contents within the myometrium and no communication with the endometrial cavity, consistent with ACUM. The patient was managed conservatively with hormonal therapy and analgesics, resulting in significant symptomatic improvement. ACUM is an important but under-recognized cause of severe dysmenorrhoea, and magnetic resonance imaging (MRI) plays a crucial role in accurate diagnosis and differentiation from other uterine anomalies.