Systemic occlusive arteriopathy with sudden death in a 10-year-old boy

A 10-year-old boy died suddenly while playing. Autopsy examination disclosed an extensive occlusive arteriopathy involving all major epicardial coronary arteries, with associated remote myocardial infarct. Also affected were the renal arteries and a branch of a pulmonary artery. The process was characterized by concentric intimal hyperplasia, focally replacing the media, with disruption of elastic laminae in more advanced lesions. The proliferating cells had ultrastructural features of smooth muscle cells. There was no evidence of atherosclerosis or vasculitis. While the case shares some features with known arteriopathies, this constellation of clinical and pathologic findings appears to be unique.