An uncommon cause of stroke in young adults.

We describe a previously healthy 48-year-old man who presented with clinical characteristics suggestive of internal carotid artery dissection, confirmed by magnetic resonance imaging. He developed a massive infarction of the left cerebral hemisphere and died after 3 days of transtentorial herniation. Post-mortem examination identified a dissection of the thoracic aorta caused by Erdheim-Gsell cystic medionecrosis, with the characteristic degeneration of the elastic fibers of the lamina media. The dissection showed an unusually large extension not only distally into both iliac arteries, but also proximally into both carotid arteries. To our knowledge, such an extensive dissection has not been described previously. Underlying vessel wall disorders of the aorta, such as Erdheim Gsell cystic medionecrosis, should be considered in young patients with spontaneous arterial dissection.