Atherosclerosis morphology

description of gross and microscopic morphology of an atherosclerotic lesion, includes fatty streak, simple plaque and fatty plaque.

1. By- Sneha A (MBBS UG ) MORPHOLOGY

2. Introduction Athero Sclerosis

3. Introduction (cont.) Distribution: infrarenal abdominal aorta > coronary arteries > popliteal arteries > internal carotid arteries > the vessels of the circle of Willis. Spared: upper extremities, renal, mesenteric (except ostia).

4. Gross Stages: Fatty streak Simple plaque Complicated plaque

5. Fatty Streak Lipid deposits in intima. Yellow, slightly raised. Fatty streaks can appear in the aortas of infants younger than 1 year and are present in virtually all children older than 10 years. Spot (1mm) -> Streak (1x10mm). The relationship of fatty streaks to atherosclerotic plaques Possible precursor of atheroma.

6. Simple plaque Intimal thickening and lipid accumulation white to yellow raised lesions ranging from 0.3 to 1.5 cm in diameter.

7. Complicated plaque (acute plaque changes) Rupture, ulceration, or erosion of the luminal surface Plaque superimposed with thrombus Lesions having undergone calcification Lesions progressing to form aneurism.

8. The six stages of atherosclerosis. (American Heart Association classification)

9. Microscopy

10. Normal v/s atherosclerotic blood vessel NORMAL (HAPPY) BLOOD VESSEL ATHEROSCLEROTIC BLOOD VESSELS

11. Microscopic parts 3 parts Fibrous cap Shoulder of cells Central necrotic core 3.NECROTIC CENTER 2.SHOULDER OF CELLS 1.FIBROUS CAPSULE

12. Fibrous cap Lies just beneath the endothelium. Composed of smooth muscle cells and relatively dense collagen.

13. Shoulder of cells Lies just beneath the fibrous cap, Consists of foamy macrophages, inflammatory cells and proliferated and recruited smooth muscle cells

14. Central core Is the soft center of the plaque. Composed of intracellular and extra cellular lipid. Some times necrosis may be seen

15. Neo-vascularisation The periphery of the plaque shows neo-vascularisation.

16. Acute plaque changes

17. Acute plaque changes (cont.)

18. To sumarise Gross 3 stages Fatty streak Simple plaque Complicated plaque microscopy 3 regions of plaque Fibrous cap Shoulder of cells Necrotic core