Hepatic Inflammatory Myofibroblastic Tumor:Comparative Study of Imaging Findings with Pathology

Objective To investigate the CT and MRI findings of hepatic inflammatory myofibroblastic tumor(HIMT) and to improve the diagnostic accuracy. Methods The imaging findings and pathological features of 9 patients with HIMT confirmed by operation and biopsy pathological examination were reviewed retrospectively. All patients underwent both the plain and contrast enhanced CT scans; 2 patients underwent both CT and MRI examination. Results Eight patients had a single lesion, 1 patient had multiple lesions and a total of 10 lesions were found. Among them, one lesion was in the left lobe, 9 lesions were in the right lobe. On plain CT scan the lesion appeared as a hypo-dense mass. 2 of the lesions on MRI T1 WI had a hypo-intense appearance, on T2 WI it had a hyper-intense appearance and was iso-intense in appearance in 7 lesions. Upon contrast enhanced T1 WI, 5 lesions demonstrated enhancement of the borders, intra-lesional septal enhancement was seen in 2 lesions and one of lesion had uniform enhancement. One of the lesions demonstrated complete lack of enhancement. One of the lesions had heterogeneous enhancement of the margins in the arterial phase while it demonstrated uniform enhancement in delayed and portal phase. One of the lesions had no enhancement in any phase. The remaining 7 lesions demonstrated no enhancement in arterial phase, minimal enhancement during the portal phase and had intense enhancement in delayed phase. On pathological examination the lesions demonstrated coagulative necrosis, the borders had plenty of fibrosis and plenty of inflammatory infiltrate. Conclusion HIMT has a characteristic appearance on imaging. CT and MRI appearance correlates with the lesions vascularity and pathological appearance. Clinical correlation can be helpful in differentiating it from other liver lesions.