A 20 year old woman with acute myocardial infarction exhibited a huge
aneurysm of the left main coronary artery that was occluded by a large
intraluminal thrombus. After exclusion of other vascular or systemic
diseases, atypical Kawasaki syndrome was diagnosed. Other major sympto
ms usually required for this diagnosis were absent. As patients with K
awasaki syndrome in childhood are surviving longer, acute coronary sym
ptoms may occur in young adults, and coronary aneurysms might be the o
nly symptom of atypical Kawasaki syndrome.