Accessory cavitated uterine mass: A rare cause of severe dysmenorrhoea managed by minimally invasive surgery

Accessory cavitated uterine mass (ACUM) is a rare congenital mullerian anomaly, encountered in young, nulliparous women. It is a non-communicating cavity, lined by functional endometrium in an otherwise normal uterus, presenting with severe intractable dysmenorrhoea. On ultrasound, it is a striking myometrial lesion but often misdiagnosed due to unfamiliarity. Though studies have described medical management, recurrence of symptoms occurs after discontinuing treatment. Surgical management, either conservative, by excising the lesion completely, or hysterectomy, can resolve the symptoms. Here, we report a 29-year old nulligravida with primary infertility presenting with severe dysmenorrhoea, unresponsive to analgesics. She was preoperatively diagnosed to have an ACUM and was managed by conservative minimally invasive surgery. Histopathology showed endometrium with secretory activity surrounded by myometrium, consistent with our findings. On postoperative follow-up, patient reported complete recovery from dysmenorrhoea. Appropriate diagnosis of this rare entity is a true challenge because of lack of awareness and the wide range of close differential diagnoses. It is imperative to understand and distinguish this peculiar lesion, with an ultimate aim of performing timely surgery, for complete symptom alleviation, especially when fertility is a concern.