Inflammatory myofibroblastic tumor (IMT) of the lung is a rare tumor but it should be considered when dealing with primary lung tumors in children, adolescents, and nonsmoking adults. It is, from a pathologic point of view, a benign tumor composed of a spindle cell proliferation and inflammatory cells. Its clinical behavior, however, is variable with a benign evolution at one, and a malignant evolution with recurrent and metastatic disease at the other end of the spectrum. Diagnosis is very difficult and often only possible after resection of the tumor. We present a case of pulmonary IMT in a 15-year-old male with malignant features on radiographic and F-Fluoro-deoxyglucose positron emission tomography imaging. Pathogenesis, pathology findings, clinical behavior, and imaging of pulmonary IMT are briefly discussed.