Wegener's granulomatosis simulates pulmonary adenocarcinoma

AbstractWegener's granulomatosis is a rare systemic granulomatous necrotizing vasculitis that characteristically involves the upper airways, lungs, and kidneys. Pulmonary Wegener's granulomatosis can present with multifocal lung involvement or solitary lung lesions. Diagnosing Wegener's granulomatosis on the basis of cytological material from sputum may be challenging for pathologists. A wrong diagnosis may lead to inappropriate treatment. We report a case of Wegener's granulomatosis in a patient who first presented with hemoptysis, poor appetite, and weight loss. Multifocal pulmonary nodules were seen on a chest radiograph and the features seen on sputum cytology were similar to those of lung adenocarcinoma. A lung biopsy sample proved granulomatous inflammation. Wegener's granulomatosis was diagnosed based on the biopsy sample and a positive cytoplasmic antineutrophil cytoplasmic antibody titer (1:1280). After treatment with prednisone and cyclophosphamide, the lung lesions resolved. We recommend measuring the cytoplasmic antineutrophil cytoplasmic antibody titer in patients with bilateral pulmonary lesions. A lung biopsy sample should always be obtained, even when the cytology findings suggest a malignancy