Inflammatory myofibroblastic tumor (IMT) is a rare benign or locally aggressive neoplasm (Kovach et al. 2006). It occurs primarily in children and young adults, but it can occur at any age (Coffin, Hornick, and Fletcher 2007). IMTs most commonly arise in the lung, abdomen, pelvis, and retroperitoneum. However, IMT also arises in other sites, including but not limited to soft tissue, CNS, and bone (Gleason and Hornick 2008).
Histologically, IMTs are characterized by the presence of a dense inflammatory infiltrate amidst spindle cells in a myxoid to collagenous stroma (Gleason and Hornick 2008). A prominent molecular feature of IMTs involves rearrangements of the ALK gene on chromosome 2p23 in approximately 50% of cases.
Treatment of IMT typically involves surgical resection (Kovach et al. 2006). IMT recurs in 25-40% of cases, but it rarely metastasizes (Kovach et al. 2006). The utility of chemotherapy in treatment of IMT has not been demonstrated (Kovach et al. 2006). The use of the ALK tyrosine kinase inhibitor crizotinib to treat advanced, recurrent, or metastatic IMT is being explored (Butrynski et al. 2010).