Segmental arterial mediolysis: a rare non-inflammatory cause of mesenteric bleeding.

Visceral abdominal aneurysms can originate from multiple disease states, including inflammatory, non-inflammatory and infectious aetiologies. It is important to follow a stepwise approach to make the correct diagnosis, because disease prognosis and management can be substantially different. We describe a 60-year-old Caucasian woman who presented from an outside facility to our University Hospital in a critical state with abdominal bleeding. She had no findings to support a vasculitic process, nor a concern for infectious aetiologies. She required a thoughtful approach and detailed imaging to diagnose a rare non-inflammatory disease as the cause for her mesenteric bleeding-segmental arterial mediolysis (SAM). Through our case and discussion, we describe the importance of recognising this rare entity and of understanding how early recognition can save patients from significant morbidity and unnecessary potential harmful therapeutic options.