Giant aneurysm of the left main coronary artery in Takayasu aortitis.

Takayasu aortitis is a chronic inflammatory vasculitis characterised by stenosis or obliteration of large and medium sized arteries. Although coronary arteries are affected in approximately 10% of cases, most of the lesions are luminal narrowing, and coronary aneurysm formation is extremely rare. A case is described of giant aneurysm of the left main coronary artery complicated with Takayasu aortitis in a 46 year old Japanese woman who was followed until her death at age 71. Pronounced intimal proliferation and adventitial fibrous thickening of the involved arterial wall usually induce constriction or occlusion at the orifice of the main branch of the aorta in Takayasu aortitis. However, systemic hypertension, which resulted from renovascular stenoses in this case, is likely to have enlarged the vessel lumen before replacement of medial and adventitial fibrosis after extensive destruction of medial elastic fibres in the left main coronary artery. Moreover, associations such as autoimmune hepatitis, chronic thyroiditis, and Sjögren syndrome strongly suggests that Takayasu aortitis may be an autoimmune disease.