Inflammatory myofibroblastic tumor of the left lower lobe invading the upper lobe ahead of fissure

We described a case of pulmonary inflammatory myofibroblastic tumor that was resected video-assisted thoracoscopic surgery (VATS) with safety surgical margin. The legion masqueraded primary lung cancer showing invasion to neighboring lobe. Positron emission tomography (PET) was not helpful in diagnosing whether it was malignant or not. Inflammatory myofibroblastic tumor was called as inflammatory pseudotumor, formerly. Several reports, however, suggested that so called inflammatory pseudotumor was a true neoplasm rather than a proliferating tissue due to inflammatory response. It is not rare that inflammatory myofibroblastic tumor invades neighboring organ or shows relapsing after coarse margin resection. Our case would remind pulmonary physicians of its correct treatment, i.e. surgical resection with adequate safety margin.