Granulomatosis with polyangiitis

Last revised by Frank Gaillard on 26 Feb 2023

Granulomatosis with polyangiitis (GPA), previously known as Wegener granulomatosis, is a multisystem necrotizing non-caseating granulomatous c-ANCA positive vasculitis affecting small to medium-sized arteries, capillaries, and veins, with a predilection for the respiratory system and kidneys.

This article discusses granulomatosis with polyangiitis in general. For organ-specific radiographic features, please refer to individual articles:

There is a slight male predilection and onset is typically at approximately 50 years of age 8.

The 1990 American College of Rheumatology criteria requires at least two of the four listed below (sensitivity 88.2% and specificity 92%) 21: 

  • positive biopsy for granulomatous vasculitis

  • urinary sediment with red blood cells 

  • abnormal chest radiograph 

  • oral or nasal inflammation 

Presentation depends on which organ systems are involved: 

  • cough and hemoptysis

  • subacute to chronic history of nasal obstruction, rhinitis, and epistaxis 

  • proteinuria and hematuria 

Symptoms related to other organ systems are less frequent, due to a corresponding infrequency of involvement (musculoskeletal symptoms, ocular symptoms, skin changes) 9.

Systemic symptoms such as anorexia, malaise and fever are also common 9.

It results from an immune-mediated vascular injury.

The classic triad of organ involvement consists of:

  • lungs: involved in 95% of cases

  • upper respiratory tract / sinuses: 75-90%

  • kidneys: 80%

In terms of extent, granulomatosis with polyangiitis can be classified as:

  • classical: full triad

  • limited: not having the full triad

    • usually respiratory tract involvement only

    • renal only involvement has been described but is uncommon 7

  • widespread: additional organ involvement 14

Histologically necrotizing granulomas with an associated vasculitis are the dominant feature.

In 90% of cases, c-ANCA (PR3) is positive and the levels correlate with disease activity 8.

Treatment is typically with cyclophosphamide, methotrexate and/or steroids. More recently, agents such as rituximab are also used.

Without treatment, granulomatosis with polyangiitis is rapidly progressive with death usually occurring within a year of diagnosis, with only 10% of patients surviving 2 years 7. Appropriate medical therapy has dramatically increased long-term survival 7.

The former name "Wegener granulomatosis" comes from the German pathologist Friedrich Wegener (1907-1990) who first described it in 1936 11,23. Wegener was a member of the Nazi party and it is suspected that he took part in, or at least was aware of, experiments on concentration camp inmates 24,25. Following the discovery of his past history, the current name "granulomatosis with polyangiitis" has been utilized 15.

General imaging differential considerations include:

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Cases and figures

  • Figure 1: gross pathology
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  • Case 1
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  • Figure 2: histology - non-caseating granuloma
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  • Case 2: with nasal septal perforation
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  • Case 3
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  • Case 4a
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  • Case 4b
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  • Case 5: CNS involvement
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  • Case 6: with paranasal and orbital involvement
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