IMT is a mesenchymal tumor characterized by spindle cell proliferation with an inflammatory infiltrate.
Approximately half of these lesions carry anaplastic lymphoma kinase (ALK) locus rearrangements on chromosome 2p23, which causes ab2242ant ALK expression.
Lesions occur primarily in the first two decades of life.
Lesions typically arise in the lung, retroperitoneum or abdominal/pelvic region.
Abdominal tumors may be multifocal.
Histologically the predominant cell is a myofibroblast in a mixoid to collagenous stroma mixed with inflammatory cells.
Associated with a low risk of distant metastases, but local recurrence may occur after surgical therapy.
Considered soft tissue tumors of its immediate biological potential.
A small percentage of cases behave aggressively.
Distant metastases occur primarily in patients that are ALK negative.
Local recurrences occur regardless of ALK expression.