What are microscopic classifications of atherosclerotic lesions?

➢ Early lesions: type I: presence of a few subendothelial foamy macrophages visible in OM type II: lipid streak (visible macroscopically) corresponding to clusters of foamy histiocytes in the intima, more numerous than before. ➢ Intermediate lesions: type III: accumulation of extracellular lipids in small quantities ➢ Advanced lesions: type IV: appearance of a lipid center, with cholesterol crystals, without fibrosis type V: classic fibro-lipid atherosclerotic plaque, type VI: complicated atherosclerotic plaque (VIa: ulceration, VIb: hemorrhage, VIc: thrombosis)