A Case of Granulomatosis with Polyangiitis Masquerading as Community Acquired Pneumonia.

Granulomatosis with polyangiitis (GPA) has a multitude of presentations, including appearing as a refractory community-acquired pneumonia (CAP) or an isolated localized pulmonary disease. This case describes a patient suspected to have a CAP before further workup and lung biopsy revealed his diagnosis of GPA. This case report demonstrates GPA's diverse presentations, critical complications such as diffuse alveolar hemorrhage (DAH) and cardiac tamponade, and nuanced management options.