Key Content

Accessory cavitated uterine malformations (ACUMs) are isolated cavitated lesions within the lateral aspect of the myometrium, inferior to the attachment of the round ligament.

They are a rare Müllerian anomaly and are increasingly recognised as a cause for severe dysmenorrhoea and pelvic pain.

ACUMs can be diagnosed with ultrasound and magnetic resonance imaging, where they appear as well-defined lesions with a central cavity containing haemorrhagic content, surrounded by a myometrial mantle. On histological examination, the cavity is lined by functional endometrial glands and stroma.

Recognised treatments include hormonal suppression, destruction of the endometrial lining by alcohol sclerotherapy, or complete surgical excision, which has demonstrated curative results.

Learning Objectives

To know what ACUMs are and recognise them as a cause of dysmenorrhoea and pelvic pain

To be able to diagnose an ACUM with the use of ultrasound, MRI and histological findings if surgically excised

To be able to counsel patients with ACUMs on the different management options, including conservative, medical and surgery

Ethical issues:

All women with ACUMs are currently offered surgical excision, but is it appropriate to offer this, to patients as young as 13 years old, with no long-term data on the effect of surgery on future fertility?