Sudden death due to giant cell coronary arteritis.

An 89-year-old woman was found dead lying in her bed. Autopsy demonstrated a pronounced thickening of all coronary arteries except for the first 2-4 cm. Death was due to a recent myocardial infarction. Microscopically, the coronary arteries showed a substantial concentric thickening of all three layers with 90% narrowing. There was a dense transmural inflammatory infiltration with lymphocytes, macrophages, and numerous multinucleated giant cells. The CD68 positive giant cells were mostly located at the media-intima border in the vicinity of fragmented fibers of the lamina elastica interna. The aorta and its major branches including the carotid arteries, however, were free of inflammation and thickening. The findings were characteristic for giant cell arteritis, the equivalent of temporal Horton arteritis, but isolated involvement of the coronary arteries is exceptional.