Aortic aneurysm due to microscopic polyangiitis.

Aortic aneurysm caused by microscopic polyangiitis is very rare. It typically affects the small vessels. We report the case of a 36-year-old woman who was diagnosed with microscopic polyangiitis as a 26-year-old and who was treated with oral hydrocortisone for 10 years, and had an ascending aortic aneurysm and severe aortic insufficiency without dilatation of the sinus of Valsalva. Laboratory analysis showed high titers of serum perinuclear anti-neutrophil cytoplasmic antibodies. She underwent replacement of the ascending aorta and aortic valve on September 21, 2006. Pathologic analysis of the aneurysmal wall revealed fibrous thickening of the adventitia and intima with severe destruction and atrophy of the media. We believe that this is the first report in the literature of a surgical case of an aortic aneurysm complicated with microscopic polyangiitis.