Granulomatosis with Polyangiitis Masquerading as Recurrent Tuberculosis and Non-Resolving Pneumonia: A rare case report

Abstract

Granulomatosis with Polyangiitis is a rare necrotizing granulomatous vasculitis that can mimic infectious or neoplastic diseases. We report a 47-year-old woman who presented with recurrent episodes of fever, cough, and non-resolving pneumonia initially treated as pulmonary tuberculosis. Despite multiple courses of antibiotics and anti-tubercular therapy, her symptoms persisted, and imaging revealed bilateral cavitating nodules. Subsequent rheumatologic evaluation showed strong proteinase-3 ANCA positivity with histological evidence of granulomatous inflammation involving the lungs, parotid gland, and upper airways. A diagnosis of GPA was established, and the patient responded dramatically to intravenous methylprednisolone followed by rituximab therapy. This case highlights the diagnostic challenges of GPA in tuberculosis-endemic regions and underscores the importance of considering vasculitic disorders in patients with recurrent or non-resolving pulmonary infiltrates unresponsive to standard therapy.