Inflammatory myofibroblastic tumor

Inflammatory myofibroblastic tumor (IMT) is a soft tissue lesion which can be found in almost all parts of the human body, but shows the highest incidence in the abdomen. It is a spindle cell lesion with prominent inflammatory infiltrate which consists predominantly of plasma cells. Using immunohistochemistry a myofibroblastic differentiation can be demonstrated. ALK is expressed in approximately 50% of tumors. The tumors are associated with a benign behavior but recurrences occur in about one third of abdominal cases. Malignant cases are rare.