Difference between revisions of "Vasculitides"

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m (→‎Small vessel vasculitides: more on definition)
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Small vessel vasculitis = vasculitis of vessels smaller than arteries; affects arterioles, venules, and capillaries.<ref name=pmid9366584>{{cite journal |author=Jennette JC, Falk RJ |title=Small-vessel vasculitis |journal=N. Engl. J. Med. |volume=337 |issue=21 |pages=1512–23 |year=1997 |month=November |pmid=9366584 |doi=10.1056/NEJM199711203372106 |url=http://www.nejm.org/doi/full/10.1056/NEJM199711203372106}}</ref>
Small vessel vasculitis = vasculitis of vessels smaller than arteries; affects arterioles, venules, and capillaries.<ref name=pmid9366584>{{cite journal |author=Jennette JC, Falk RJ |title=Small-vessel vasculitis |journal=N. Engl. J. Med. |volume=337 |issue=21 |pages=1512–23 |year=1997 |month=November |pmid=9366584 |doi=10.1056/NEJM199711203372106 |url=http://www.nejm.org/doi/full/10.1056/NEJM199711203372106}}</ref>
*What is an arteriole?
*What is an arteriole?
**There is no histologic definition according to Sternberg's Histology for Pathologists; however, <100 micrometers is suggested as a definition.<ref>{{Ref H2P|769}}</ref>
**There is no histologic definition according to Sternberg's Histology for Pathologists; however, <100 micrometers is suggested as a definition.<ref name=Ref_H4P2>{{Ref H4P2|769}}</ref>


=====Types=====
=====Types=====

Revision as of 22:17, 26 November 2010

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

Overview

Most common[1]

  • Polyarteritis nodosa (PAN).
  • Microscopic 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, <100 micrometers is suggested as a definition.[3]
Types
  • Predominantly cutaneous vasculitis.
  • Henoch-Schoenlein purpura.
  • Essential cryoglobulinemic vasculitis.
  • ANCA-associated:
    • Wegener's granulomatosis (c-ANCA > p-ANCA).
    • Churg-Strauss syndrome (50% ANCA +ve).
    • Microscopic polyangiitis (usually p-ANCA).

Notes:

  • ANCA = anti-neutrophil cytoplasmic antibodies.

Medium vessel vasculitides[4]

  • Polyarteritis nodosa (PAN).
  • Kawasaki disease.

Large vessel vasculitides[4]

  • Giant cell arteritis (AKA temporal arteritis).
  • Takayasu's arteritis.

Pathologist's role in the diagnosis of vasculitis

General

  • Pathologists often cannot, based on morphology alone, arrive at the definitive diagnosis.
  • Presentation & distribution are more characteristic than pathology.[5][6]

Microscopic

Features:[7]

  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.[8]
      • "Nuclear dust" = punctate hyperchromatic material ~ 1 micrometre.

Giant cell arteritis

General

  • AKA temporal arteritis.

Clinical

Features:

  • Classic finding: jaw claudication, in a patient older than 50 years.
  • Other findings: headache, vision loss or diplopia, scalp tenderness, polymyalgia, weight loss, chills, fever.

Work-up:

  • CRP, ESR, temporal artery biopsy.

Treatment:

  • Treat right away with high dose steroids.
    • Biopsy is confirmatory.

Micrograph

Features:

  • Classical: granulomas.

Image(s):

Takayasu's arteritis

General

Features:[9]

  • 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.

Microscopic

Features:[9]

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

Polyarteritis nodosa

General

  • Abbreviated PAN.
  • Involves small and medium sized vessels.
  • Often - renal vessels, mesenteric vessels.[10]
  • Strong association with hepatitis B (see medical liver diseases); ~1/3 of patients with PAN have HBV.

Serology:

  • ANCA is usually negative.

Microscopic

Features:

  • Inflammatory cells (neutrophils, lymphocytes) within the tunica media.
  • Fibroid necrosis: dead vessel wall - pink anucleate stuff, nuclear debris (black specks of nuclear material).

Image: PAN (immunologyclinic.com).

Wegener's granulomatosis

Clinical

  • Epistasis.
  • Renal failure - present as nephritic syndrome.
    • Renal biopsy: crescentic glomerulonephritis (AKA rapidly progressive glomerulonephritis).
  • Pulmonary hemorrhage.

Serology:

Notes:

  • Pulmonary hemorrhage syndromes:[12]
    • Goodpasture syndrome.
    • Idiopathic pulmonary hemosiderosis.
    • Vasculitis-assoc. hemorrhage (hypersensitivity angiitis, Wegener's granulomatosis).
    • Systemic lupus erythematosus.

Microscopic

Features:

  • Granulomas typically poorly formed.[13]

Image: Wegener's granulomatosis (flickr.com).

See also

References

  1. TN05 RH3.
  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. URL: http://www.pathology.ubc.ca/path425/PrincipleofPathophysiology/CirculatoryDisorders/SystemicVasculitisDrBWalker.doc. Accessed on: 26 November 2010.
  6. URL: http://www.icapture.ubc.ca/who/who_bios_david_walker.shtml. Accessed on: 26 November 2010.
  7. URL: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908435/. Accessed on: 26 November 2010.
  8. URL: http://dictionary.weather.net/dictionary/amorphous. Accessed on: 26 November 2010.
  9. 9.0 9.1 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.
  10. Klatt, Edward C. (2006). Robbins and Cotran Atlas of Pathology (1st ed.). Saunders. pp. 14. ISBN 978-1416002741.
  11. TN05 RH6.
  12. 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. 745. ISBN 0-7216-0187-1.
  13. 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. 747. ISBN 0-7216-0187-1.