The CT and pathological features of intestinal inflammatory myofibroblastic tumor

Abstract

Abstract To explore computed tomography (CT) findings and pathological features of intestinal inflammatory myofibroblastic tumors (IMT). A retrospective review was conducted on the CT features of five patients with pathologically confirmed IMT, which were then compared with the corresponding pathological findings. The study included four female and one male patients. The tumors were located in the rectum (n = 1), small intestine (n = 2), or cecum (n = 2). One patient exhibited a cystic solid mass with exophytic growth and the solid components showed moderate enhancement. Additionally, flaky low‐density, marginal line‐like calcified shadows were observed around the lesions. Two cases presented as solid masses within the lumen of the intestinal tract, showing obvious non‐uniform enhancement along with visible enhancement shadows of small blood vessels. One patient had a metastasis. In two other cases, solid masses grew outside the lumen of the intestinal tract, demonstrating progressive and delayed enhancement on enhanced scans, as well as local nodular enhancement and ring enhancement. These two cases also exhibited focal sarcomatoid lesions, along with their respective IMTs. Histologically, these tumors mainly consist of proliferating spindle myofibroblast cells accompanied by variable infiltration by interstitial inflammatory cells, such as fibroblasts. Immunohistochemical analysis revealed positive staining for smooth muscle actin (SMA) in ~80% of the cells tested, while vimentin staining was positive in ~60% of the cells. Intestinal IMT is an extremely rare tumor with imaging features that can reflect the underlying pathological characteristics to some extent, thus aiding diagnosis.

Keywords

• CT
• inflammatory myofibroblastic tumor
• intestinal tumor