Abstract:We reported a successful diagnosis and treatment of a 65-year-old male patient with pulmonary lesion caused by antineutrophil cytoplasmic antibody (ANCA) associated vasculitis. The main manifestations of the patient were chronic cough and pulmonary migratory shadows. He was once diagnosed as lymphocytic interstitial pneumonia, and received effective corticosteroid mono-treatment. MPO-ANCA was positive after the disease relapsed, and ultimately, the diagnosis of ANCA associated vasculitis was made after lung puncture biopsy. After combination administration of corticosteroid and cyclophosphamide, all signs and symptoms were relieved. According to literature and our clinical experience, ANCA associated vasculitis had complex, non-specific clinical manifestations, and thus, was often misdiagnosed. In order to facilitate the early diagnosis of this disease, respiratory physicians should be familiar with the characteristics of the pulmonary involvement of ANCA associated vasculitis, and pay more attention to serum ANCA screening.