Aortic aneurysms may occur in association with atherosclerosis. The section demonstrates an atherosclerotic plaque overlying the aortic media. The core of the plaque is composed mainly of lipid-laden macrophages.
Stippled calcification is also evident.
The lamellated surface of the plaque is the fibrous cap. This section has been stained for fat, which shows up as black, globular material. Lipid streaks have been observed in the vessels of very young children, and may represent precursor lesions in the development of atherosclerosis. These flat to slightly raised lesions on the intimal surface are composed mostly of lipid-filled macrophages and small amounts of collagen and proteoglycans.