Pulmonary consolidation with fever is not always pneumonia: A case of microscopic polyangiitis and review of the literature

SummaryMicroscopic polyangiitis is a non-granulomatous, systematic and small-vessel vasculitis in which necrotizing glomerulonephritis is very common and pulmonary capillaritis often occurs. We report a patient with fever, fatigue and dry cough who initially had been diagnosed as having pneumonia. A thoracic CT was performed showing widespread multiple nodular lesions, some with a central air-bronchogram and thickened bronchovascular bundles and some connected to nodules. No cavitation or ground glass opacities were observed. Fibreoptic bronchoscopy was normal and the cultures from the BAL were negative. Additionally, during his stay in the hospital his hematocrit was gradually falling, while the erythrocyte sedimentation rate increased. Urinanalysis revealed proteinuria and active urinary sediment. p-ANCA was positive and renal biopsy revealed focal pauci-immune necrotic glomerulonephritis. Pulmonary–renal syndrome was suspected and renal biopsy was performed. The diagnosis of microscopic polyangiitis was established and the patient began treatment with pulse intravenous methylprednisolone and cyclophosphamide. After induction of remission, the patient received maintenance therapy. Finally, an extensive review of the literature on microscopic polyangiitis is presented.