Pulmonary vasculitides are a group of diseases that all have inflammation and loss of pulmonary blood vessels in common. Granulomatosis with polyangiitis (GPA), formerly known as Wegener granulomatosis, is one of the most prevalent antineutrophil cytoplasmic antibodies–associated small-vessel vasculitis that affects several organ systems. GPA affects people of all ages, although it usually manifests itself in middle adulthood. The typical GPA trio of upper airway involvement, lower respiratory tract illness, and glomerulonephritis is not always present at presentation. Furthermore, there are restricted types of GPA that do not have the typical upper airway and renal involvement. Multiple, bilateral nodules or masses, usually with cavitation or necrosis, are typical imaging symptoms of GPA. There may be diffuse lung opacity owing to alveolar bleeding or tracheobronchial inflammation, which can lead to stenosis. When cytoplasmic antineutrophil cytoplasmic antibody/anti-proteinase 3 antibodies are detected in the appropriate clinical context, systemic GPA can be diagnosed; however, most GPA diagnoses rely on recognising a combination of common clinical, laboratory, and imaging findings with typical histopathologic changes noted from a biopsy of the affected tissue.

To elicit and sustain remission in GPA patients, a combination of corticosteroids and immunomodulatory drugs is employed. Although GPA is potentially deadly if left untreated, immunosuppressive treatment has significantly improved survival in people with the disease.