Atherosclerosis

 

Epidemiology:

    • Risk increases with age
    • M > F

 

Common sites:

    • abdominal aorta > thoracic aorta
    • ostia of major branches
    • coronaries
    • popliteals
    • internal carotid
    • circle of Willis

 

Gross features:

    • atheromas and atheromatous plaques (fibrofatty plaques)
      • soft, yellow, grumous core (lipid)
      • firm, white fibrous cap
      • eccentrically located
      • patchy and variable along the length of the vessel

 

Histologic features:

    • intimal thickening
    • lipid accumulation
    • 3 components:
      • cells – smooth muscle cells, macrophages, leukocytes
      • ECM – collagen, elastic fibres, proteoglycans
      • Lipid – intracellular and extracellular
    • Superficial fibrous cap:
      • Smooth muscle cells and dense ECM
    • “shoulder” – beneath and to the side of the cap
      • cellular area – macrophages, smooth muscle cells, T cells
    • necrotic core:
      • lipid (cholesterol and cholesterol esters), cholesterol clefts
      • cellular debris
      • foam cells
      • fibrin
      • thrombus
      • plasma proteins
      • calcification
    • neovascular periphery:
      • proliferating small blood vessels
    • type I (initial) lesion:
      • isolated foamy macrophages
    • type II (fatty streak) lesion:
      • foamy macrophages (lipid-filled) in the intima
      • T cells
    • type III (intermediate) lesion:
    • type IV (atheroma) lesion:
    • type V (fibroatheroma) lesion:
    • type VI (complicated) lesion:
      • rupture, ulceration, or erosion of the luminal surface
      • thrombus formation superimposed
      • hemorrhage into a plaque
      • atrophy of underlying media with loss of elastic tissue
        • aneurismal dilation / potential rupture

 

Immunophenotype:

Marker:

Sensitivity:

Specificity:

 

 

 

 

Molecular features:

    • polygenic influences

 

Other features:

    • risk factors:
      • age
      • sex
      • family history
      • hypercholesterolemia
      • lhypertension
      • smoking
      • diabetes
      • homocystinuria

 

References:

    •