A 79-year-old man was admitted through the medical take with norovirus gastritis. Routine plain chest radiography demonstrated a right coin lesion. CT and subsequent positron emission tomography showed a right upper lobe mass consistent with primary bronchial carcinoma. The lesion was resected and histology revealed a granulomatous necrotising mass without evidence of dysplasia. Meticulous investigations for infectious and non-infectious causes of necrotising granulomatous diseases were repeatedly negative. His postoperative recovery was complicated by a hospital-acquired pneumonia and a pulmonary embolism. CT pulmonary angiography showed progression of the previously resected mass and repeat biopsy was similar to the initial. A clinical diagnosis of antineutrophil cytoplasmic antibody-negative vasculitis without extrapulmonary manifestations was made and immunosuppressive therapy was initiated with rapid clinical response.