An 80-year-old man with long-standing diabetes and systemic hypeension dies of congestive hea failure. The luminal surface of the abdominal aoa shows atherosclerotic plaques. Which of the following is not a principal component of such plaques?

Atherosclerosis is a disease of large- and medium-sized elastic and muscular aeries that results in the progressive accumulation within the intima of inflammatory cells, hyperplastic smooth muscle cells, lipids and connective tissue. The resulting characteristic lesion, the lipid plaque (atheroma), contains pools of extracellular lipid and numerous lipid-laden macrophages (foam cells). It is not an acute inflammatory or infectious process. Atherosclerotic plaques have four principal components: cells including variable numbers of smooth muscle cells, macrophages, and T lymphocytes extracellular matrix (ECM) including collagen, elastic fibers, and proteoglycans intracellular and extracellular lipids calcifications in later stage plaques