Granulomatosis With Polyangiitis Presenting as Pulmonary Nodules: A Case Study and Literature Review.

This article presents a case of myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA)-positive granulomatosis with polyangiitis (GPA) presenting initially as chronic cough. Pulmonary shadows persisted and progressed despite antibiotic therapy. The diagnosis was confirmed by lung biopsy showing granulomatous inflammation with vasculitis, and the patient improved significantly with glucocorticoids combined with cyclophosphamide. This report, supplemented by a review of relevant literature, aims to enhance clinical awareness of this disease and emphasizes the importance of considering vasculitis and obtaining pathological confirmation in cases of refractory pulmonary lesions.