Aortic fibromuscular dysplasia complicated by dissection: a case report and review of literature.

Fibromuscular dysplasia (FMD) is an idiopathic, segmental, nonatherosclerotic, non-inflammatory vascular disease, which is often complicated by the occurrence of dissection. Although it is known to occur in all arteries, aortic involvement is relatively rare. To date, 33 cases of aortic FMD have been reported in available English literature, among which only three cases have been complicated by the occurrence of dissection. We describe the case of a 40-year-old woman diagnosed with aortic FMD complicated by the occurrence of a type A aortic dissection. Non-invasive imaging revealed an ascending to descending thoracic aneurysm measuring 8 cm in diameter associated with dissection. Histopathologically, a segment of the wall of the aneurysm showed architectural disorganization of the aortic wall with loss of elastic fibers, collagen deposition, and irregular proliferation of smooth muscle cells in the intima and media-features suggesting FMD. No atheromatous plaque or medial cystic degeneration was observed in the aorta. Although aortic FMD is sometimes fatal, it is often very difficult to diagnose using imaging techniques. Therefore, performing a histopathological diagnosis is very important and should be emphasized.