Granulomatosis with Polyangiitis
Brian J. Hall, MD
Key Facts
Clinical Issues
Correlation of clinical and histologic (most commonly LCV) findings with ANCA serology (most often PR3/c-ANCA positivity) can allow for diagnostic findings of GPA in most cutaneous lesions
Microscopic Pathology
Findings can be quite nonspecific (50% of cases in 1 study) with only approximately 20% of cases showing classic necrotizing, granulomatous vasculitis
Leukocytoclastic vasculitis is very common finding in skin biopsies
Ancillary Tests
PR3/c-ANCA is positive in 75-90% of patients with active/systemic GPA and is considered highly sensitive in detecting active, systemic disease
Lack of PR3/c-ANCA positivity can not exclude disease
 Early gangrenous changes of the digits on the hand are present here secondary to granulomatous vasculitis of GPA. |
 This biopsy of cutaneous GPA shows extravascular fibrinoid material  , karyorrhexis  , RBC extravasation  , and fibrinoid necrosis of vessels  . (Courtesy K. Duffy, MD.) |
TERMINOLOGY
Abbreviations
Granulomatosis with polyangiitis (GPA)
Synonyms
Wegener granulomatosis, Wegener
Definitions
Systemic disease characterized by generalized necrotizing angiitis of medium-sized blood vessels, necrotizing granulomas of upper and lower respiratory tract, and focal necrotizing glomerulonephritis
ETIOLOGY/PATHOGENESIS
Unknown
Thought to represent autoimmune inflammatory process or hypersensitivity reaction to possible unknown antigen(s)
CLINICAL ISSUES
