Two patients with microscopic polyangiitis and unusual pulmonary manifestation

We encountered two patients with microscopic polyangiitis (MPA) associated with unusual pulmonary manifestations. The first patient was a 45-year-old man who had worked in amine for 3 years when he was young. On admission, chest X-rays showed long-standing silicosis and a new patchy infiltration. The second patient was a 52-year-old female. On admission, chest X-rays showed bilateral patchy infiltrations. Since then, variable patterns of patchy infiltration have waxed and waned repeatedly. The renal biopsy revealed that both patients had glomerulonephritis associated with small vessel vasculitis but with few or no immune deposits. There was neither granulomatous inflammation nor eosinophilic infiltration. Myeloperoxidase-antineutrophil cytoplasmic antibody (ANCA) was positive in both patients. After treatment with glucocorticoids and cyclophosphamide, radiological findings were minimal and stable. These two cases show that patients with MPA have a wide spectrum of radiological findings.