abdominal inflammatory myofibroblastic tumor

Inflammatory myofibroblastic tumor (IMT) occurring in abdominal location is a rare condition in children.

Inflammatory myofibroblastic tumor (IMT) is a proliferative lesion composed of spindle cells accompanied by inflammatory infiltrate.

Synopsis

 infiltrative growth pattern
 variable admixture of spindle (myofibroblastic and fibroblastic) cells and
predominantly mononuclear inflammatory cells
 possible compact fascicular spindle cell proliferation with collagenized matrix and a distinct focal or sparse inflammatory infiltrate resembling a fibromatosis-like proliferation
 possible spindle cells to plump cells in an edematous myxoid background with scattered lymphocytes, plasma cells, eosinophils and small blood vessels, resembling a granulation tissue.
 possible foci of necrosis
 rare atypical tumor cells
 low mitotic index (@<@1/10 HPF-high power fields)
 no ganglion-like cells, Reed-Sternberg-like cells or calcification/ossification foci

Immunochemistry

 ALK+
 Strong diffuse vimentin and focal to diffuse smooth muscle actin was observed in the cytoplasm of spindle cells
 focal desmin+

Localization

 gastric
 hepatic
 colonic
 splenic adrenal
 pancreatic