English: High magnification micrograph of a vasculitic neuropathy, also neuropathy due to a vasculitis. Resin section (plastics) with toluidine blue stain.

The pathologic features of vasculitic neuropathy are evident:

• Zonal involvement of the nerve fascicles with:
  • Loss of myelin.
  • Wallerian degeneration.
  • Regeneration.

Chronic active vasculitis:

• Active features:
  • Perivascular and mural inflammatory infiltrate including lymhocytes and histocytes.
  • Plump (reactive) endothelial cells.
  • Vessel wall cell death (necrosis).
• Chronic features:
  • Vessel wall thicking due to hyperplasia.
  • Dense fibrous tissue around the vessel.

The vasculitis in this case affects both small (< 100 micrometers) and medium vessels. Granulomas are absent. Eosinophils are rare. Histomorphologic, diagnostic considerations are polyarteritis nodosa and microscopic polyangiitis.

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  Low mag.
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  Intermed. mag.
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  High mag.

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  Intermed. mag.
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  High mag.
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  Very high mag.