Vasculitis

VASCULITIS

Early lesion
Fibrinoid necrosis
Inflammation
Occluded vessels
Recanalized vessels

VASCULITIC LESION: EARLY

Inflammation around vessel wall

Macrophage inflammation (acid phosphatase positive) in vessel endothelium

Relatively intact structure of vessel wall

H&E stain

Acid phosphatase stain

Acid phosphatase stain

FIBRINOID NECROSIS

Eosinophilic, homogenous, & refractile staining in inner regions of vessel wall

Endothelial components

Can be seen inside the layer of fibrinoid necrosis

Endothelial cell nuclei may be enlarged

Inner ring of elastin is damaged

H&E stain

H&E stain

H&E stain

VvG stain

Toluidine blue stain

Alkaline phosphatase stain

VASCULITIS: Occluded Vessels

Lumen is replaced by connective tissue

Inflammation remains surrounding vessel

Macrophages (acid phosphatase staining cells) are relatively scarce

Alkaline phosphatase staining

Present around vessels in connective tissue

No endothelial structures stained

H & E stain

H & E stain

H & E stain

VvG stain

Toluidine blue stain

Toluidine blue stain

Acid phosphatase stain

Alkaline phosphatase stain

VASCULITIS: Recanalized (Chronic) Vessels

Several lumens surrounded by cells appear in center of intermediate-sized vessel

New vessels also appear in connective tissue surrounding vessel intermediate-sized
Alkaline phosphatase stains rim (?endothelium) of new vessels

VvG stain	H & E stain	Alkaline phosphatase stain
Gomori trichrome stain

VvG stain

Toluidine blue stain

VASCULITIS: Other features

H & E stain Inflammation T-cells surround vessel Giant cells or granulomas may be present Inflammatory cells in vessel wall may be fragmented	H & E stain
Gomori trichrome stain Differential fascicular involvement of nerve One fascicle has fewer axons than the others

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1/11/2012