A Case of Pulmonary Adenocarcinoma Developed on a Previous Lesion from Microscopic Polyangiitis

This report examines a patient with pulmonary adenocarcinoma that developed on a previous lesion from microscopic polyangiitis. A 59-year-old woman had been diagnosed with microscopic polyangiitis in October of 1988 based on her clinical symptoms and serological tests, which were positive for antineutrophil cytoplasmic antibodies. Her glomerulonephritis had been well controlled with low-dose prednisolone. She presented in October of 2005 with vague chest discomfort and dyspnea on exertion. Physical examination was unremarkable. A non-contrast computed tomography (CT) scan of the chest showed patch ground-glass opacity at the right lower lobe of the lung. Because we did not believe the lesion to be a definite malignancy, we decided to follow up with chest images over a short interval. During the 18 months following the images, the lesion did not change. However, the opacity of the lesion increased slightly over the last two months, and a non-contrast CT scan of the chest was therefore performed. A CT scan showed persistent ground-glass opacity with a slightly solid portion. To diagnose the previous finding and possibly to provide treatment, a right lower lobectomy of the lung via video-assisted thoracoscopic surgery was performed. The pathologic review of the resected lung revealed an adenocarcinoma, stage pT1N0. After one year, fluorodeoxyglucose positron emission tomography was performed, and no evidence of a recurrent malignancy was found.