Cystic medial necrosis

Cystic medial necrosis (also referred to as cystic medial degeneration) is a disorder of large arteries. A degenerative breakdown of collagen, elastin, and smooth muscle caused by aging contribute to weakening of the wall of the artery.

In the aorta,this can result in the formation of a fusiform aneurysm. There is also increased risk of aortic dissection.

There is an association between cystic medial necrosis and Marfan syndrome.

Terminology
It is sometimes called "Erdheim's cystic medial necrosis", after Jakob Erdheim.

The term "cystic medial degeneration" is sometimes used instead of "cystic medial necrosis", because necrosis is not always found. However, the findings are not always cystic either, making the terminology complex. (See eMedicine article for more details.)