Segmental arterial mediolysis, a vasculitis mimic: Case report and review of literature

Segmental Arterial Mediolysis (SAM) is a non-inflammatory vascular condition that most commonly affects the medium sized vessels in the abdomen including splanchanic and renal arteries. Its angiographic appearance closely mimics other conditions affecting these blood vessels, such as polyarteritis nodosa (PAN), infections such as syphilis and fibromuscular dysplasia. SAM is under-recognized, however it is important to distinguish it from PAN because the management of the two conditions differs significantly. Here we report a case of a woman presenting with intra-abdominal bleeding, with imaging evidence for large retroperitoneal hematoma. Arteriography revealed diffuse, segmental dilation and aneurysms of the arterial supply to the entire colon. Discussion includes review of current understanding of physiopathology, clinical features, imaging, and differential diagnosis of this rare disease. Recent highlights on the disease course are also discussed.