Vasculitides

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Micrograph showing a vasculitis. H&E stain.

This article deals with the vasculitides (singular vasculitis). Vascular disease that is not vasculitides is covered in the article vascular disease.

The histology of normal vessels is dealt with in normal blood vessels.

Overview

Most common[1]

  • Polyarteritis nodosa (PAN).
  • Microscopic polyangiitis.
  • Granulomatosis with polyangiitis (Wegener's granulomatosis).
  • Predominantly cutaneous vasculitis.
  • Giant cell arteritis (GCA).

Grouping by size

Small vessel vasculitides

Definition

Small vessel vasculitis = vasculitis of vessels smaller than arteries; affects arterioles, venules, and capillaries.[2]

  • What is an arteriole?
    • There is no histologic definition according to Sternberg's Histology for Pathologists; however, a diameter of <100 micrometers is suggested as a definition.[3]
Types

Notes:

  • ANCA = anti-neutrophil cytoplasmic antibodies.
    • The terminology has changed as more knowledge has been gained:
      • MPO-ANCA = p-ANCA.
      • PR3-ANCA = c-ANCA.

Medium vessel vasculitides[4]

Large vessel vasculitides[4]

Grouping by hypersensitivity

Cell-mediated hypersensitivity:[5]

  • Giant cell arteritis.
  • Takayasu arteritis.
  • Eosinophilic granulomatosis with polyangiitis (Churg-Strauss disease).
  • Granulomatosis with polyangiitis (Wegener’s granulomatosis).

Note:

  • All have granulomas.

Immune complex mediated hypersensitivity:[5]

Pathologist's role in the diagnosis of vasculitis

General

  • Pathologists often cannot, based on morphology alone, arrive at the definitive diagnosis.
  • The presentation & distribution are more characteristic than the pathology.[6][7]

Microscopic

Features - both #1 and #2 are required:[8]

  1. Inflammatory cells within the blood vessel wall.
  2. Vessel injury:
    • Frank fibrinoid necrosis or nuclear dust:
      • Fibrinoid necrosis = anucleate amorphous intensely eosinophilic material.
        • Amorphous = no definite form.[9]
      • "Nuclear dust" = punctate hyperchromatic material ~ 1 micrometre.

Notes:

  • Involvement is usually patchy.
    • If there is an inkling of vasculitis... it should prompt deeper cuts.

Features to consider

  1. Presence of granulomas.
  2. Type inflammatory cells, i.e. eosinophils, mononuclear cells.
  3. Size of vessels involved.
  4. Extent of involvement.
  5. Acuity (acute vs. subacute vs. chronic vs. acute on chronic).
    • Chronic = thick fibrotic appearing vessels with a small lumen.

Vasculitis versus neuropathy

Domain Vasculitis Neuropathy
Clinical pain, diffuse/
patchy distribution 		focal/isolated
Pathological
(inflammatory cells) 		epineurium endoneurium

Small vessel vasculitides

The follow section has information specific to the individual types of small vessel vasculitis.

Small vessel leukocytoclastic vasculitis

  • AKA leukocytoclastic vasculitis, abbreviated LCV.
Main article: Small vessel leukocytoclastic vasculitis

Microscopic polyangiitis

General

  • Classically MPO-ANCA (p-ANCA) +ve.

Microscopic

Features - small-sized vessels with:

  • Inflammatory cells (neutrophils, lymphocytes) within the tunica media.
  • Fibroid necrosis: dead vessel wall - pink anucleate stuff, nuclear debris (black specks of nuclear material).
  • No granulomas.

Images:

Granulomatosis with polyangiitis

Previously known as Wegener granulomatosis.
Main article: Granulomatosis with polyangiitis

Eosinophilic granulomatosis with polyangiitis

Previously known as Churg-Strauss syndrome and Churg-Strauss disease.
Main article: Eosinophilic granulomatosis with polyangiitis

Medium vessel vasculitides

The follow section has information specific to the individual types of medium vessel vasculitis.

Kawasaki disease

General

  • Medium vessel disease.
  • Classically afflicts the coronary arteries of children - usu. less than 5 years old.
    • May lead to coronary artery aneurysms.[10]

Clinical features - mnemonic Warm CREAM:[11]

  • Warm = fever.
  • Conjunctivitis, non-exudative.
  • Rash, polymorphous.
  • Erythema or edema of hands and feet.
  • Adenopathy, usu. cervical and unilateral.
  • Mucosal manifestations - strawberry tongue, cracked lips.

Treatment:

  • High dose IV aspirin.

Microscopic

Features:

  • Medium-sized vessels with intramural inflammatory cells.
  • Vessel destruction, e.g. fibrinoid necrosis (very pink anucleate arterial wall).

Polyarteritis nodosa

  • Abbreviated PAN.

General

  • Involves small and medium sized vessels.
  • Often - renal vessels, mesenteric vessels.[12]
    • Classically, lung involvement by PAN is considered to be rare, though this may not be entirely true.[13]
  • Strong association with hepatitis B (see medical liver diseases); ~1/3 of patients with PAN have HBV.

Serology:

  • ANCA is usually negative.

Microscopic

Features - medium-sized vessels with:

  • Inflammatory cells (neutrophils, lymphocytes) within the tunica media.
  • Fibroid necrosis: dead vessel wall - pink anucleate stuff, nuclear debris (black specks of nuclear material).
    • Usu. focal (wall) involvement; classically leads to berry microaneurysms - ergo the name polyarteritis nodosa.

Image:

Large vessel vasculitides

The follow section has information specific to the individual types of large vessel vasculitis.

Giant cell arteritis

Temporal artery redirects here.
  • Abbreviated GCA.
  • AKA temporal arteritis.
Main article: Giant cell arteritis

Takayasu arteritis

General

Features:[14]

  • Disease of medium/large arteries.
    • Classically involves the aortic arch - leading to decreased pulses in the upper limbs.
  • Typically in patients <40 yrs old.
  • Usually Asian.

Pathogenesis:

Gross

Features:[14]

  • Classically involves the aortic arch.

Microscopic

Features:[14]

  • Adventitial mononuclear infiltrate with perivascular cuffing of the vasa vasorum.
  • Mononuclear inflammation in media.
  • Granulomas, giant cells.
  • +/-Patchy necrosis of media.

Other

Aortitis

General

  • Uncommon.

Gross

Features:

  • Tree bark-like appearance.

Notes:

  • Several blocks should be submitted.

Image:

Microscopic

Features:

  • Inflammatory cells.

Subclassification:

  • Granulomatous.
  • Lymphoplasmacytic pattern.
  • Mixed inflammatory.
  • Suppurative.

LAMP-2 vasculitis

  • Associated with pauci-immune necrotizing and crescentic glomerulonephritis.[18]
  • Grouped with the ANCA-associated vasculitides.[19]

See also

References

  1. ↑ Yeung, J.C.; Leonard, Blair J. N. (2005). The Toronto Notes 2005 - Review for the MCCQE and Comprehensive Medical Reference (2005 ed.). The Toronto Notes Inc. for Medical Students Inc.. pp. RH3. ISBN 978-0968592854.
  2. ↑ Jennette JC, Falk RJ (November 1997). "Small-vessel vasculitis". N. Engl. J. Med. 337 (21): 1512–23. doi:10.1056/NEJM199711203372106. PMID 9366584. http://www.nejm.org/doi/full/10.1056/NEJM199711203372106.
  3. ↑ Sternberg, Stephen S. (1997). Histology for Pathologists (2nd ed.). Lippincott Williams & Wilkins. pp. 769. ISBN 978-0397517183.
  4. ↑ 4.0 4.1 Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 512. ISBN 978-1416031215.
  5. ↑ 5.0 5.1 URL: http://dermind.tripod.com/vasculitis.htm. Accessed on: 30 April 2012.
  6. ↑ URL: http://www.pathology.ubc.ca/path425/PrincipleofPathophysiology/CirculatoryDisorders/SystemicVasculitisDrBWalker.doc. Accessed on: 26 November 2010.
  7. ↑ URL: http://www.icapture.ubc.ca/who/who_bios_david_walker.shtml. Accessed on: 26 November 2010.
  8. ↑ Dillon, MJ.; Eleftheriou, D.; Brogan, PA. (Sep 2010). "Medium-size-vessel vasculitis.". Pediatr Nephrol 25 (9): 1641-52. doi:10.1007/s00467-009-1336-1. PMC 2908435. PMID 19946711. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908435/.
  9. ↑ URL: http://dictionary.weather.net/dictionary/amorphous. Accessed on: 26 November 2010.
  10. ↑ Taubert, KA.; Shulman, ST. (Jun 1999). "Kawasaki disease.". Am Fam Physician 59 (11): 3093-102, 3107-8. PMID 10392592.
  11. ↑ URL: http://www.medicalmnemonics.com/cgi-bin/return_browse.cfm?&system=Other%2FMiscellaneous&discipline=Pathology&browse=1. Accessed on: 14 January 2012.
  12. ↑ Klatt, Edward C. (2006). Robbins and Cotran Atlas of Pathology (1st ed.). Saunders. pp. 14. ISBN 978-1416002741.
  13. ↑ Matsumoto, T.; Homma, S.; Okada, M.; Kuwabara, N.; Kira, S.; Hoshi, T.; Uekusa, T.; Saiki, S. (Jul 1993). "The lung in polyarteritis nodosa: a pathologic study of 10 cases.". Hum Pathol 24 (7): 717-24. PMID 8100552.
  14. ↑ 14.0 14.1 14.2 Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Nelso Fausto; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease (7th ed.). St. Louis, Mo: Elsevier Saunders. pp. 538. ISBN 0-7216-0187-1.
  15. ↑ Arnaud, L.; Haroche, J.; Mathian, A.; Gorochov, G.; Amoura, Z. (Nov 2011). "Pathogenesis of Takayasu's arteritis: a 2011 update.". Autoimmun Rev 11 (1): 61-7. doi:10.1016/j.autrev.2011.08.001. PMID 21855656.
  16. ↑ URL: http://dermind.tripod.com/vasculitis.htm. Accessed on: 30 April 2012.
  17. ↑ Vaideeswar, P.. "Syphilitic aortitis: rearing of the ugly head.". Indian J Pathol Microbiol 53 (4): 624-7. doi:10.4103/0377-4929.72002. PMID 21045381.
  18. ↑ Bosch X, Mirapeix E (May 2009). "Vasculitis syndromes: LAMP-2 illuminates pathogenesis of ANCA glomerulonephritis". Nat Rev Nephrol 5 (5): 247–9. doi:10.1038/nrneph.2009.51. PMID 19384321. http://www.nature.com/ki/journal/v76/n1/abs/ki2009123a.html.
  19. ↑ Chen M, Kallenberg CG (2009). "New advances in the pathogenesis of ANCA-associated vasculitides". Clin. Exp. Rheumatol. 27 (1 Suppl 52): S108–14. PMID 19646356.
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