Abstract: Inflammatory myofibroblastic tumor (IMT) has been recognized and formally described as an inter-mediate type of tumor with low potential malignancy, comprising a range of diagnoses from pathological changes involved in inflammatory reactions to tumors. It is found in all parts of the human body, usual-ly presenting with a clinical manifestation of a local lump and general symptoms such as fever, weightloss, night sweats and lymphadenectasis, etc. It has unifocal or multifocal symptoms with a capacity for regional infiltrative growth, vascular invasion, local recurrence and even rapid development, causing ac-celerated death in a few cases. The tumors can be of considerable size and are capable of infiltrative growth, mimicking a malignant tumor clinically and radiologically. Myofibroblast, lymphocyte, plasmo-cyte, eosinophil granulocyte, histiocyte, mucous interstitium, and vascular or collagenous fiber in vary-ing amounts can be found microscopically. These features mimic inflammatory reactive hyperplasia andalso, but less so, necrosis, cellular dysplasia and fascicular sarcoma. The exact etiology of this lesion isunknown. There is expression of anaplastic lymphoma kinase (ALK) in IMT resulting from a fusion of the ALK gene to the Ran-binding protein 2 (RANBP2) gene. The diagnostic process, genetics, patholo-gy, radiology, and clinical behavior of IMT is described herein.