CT imaging features and pathological manifestations of inflammatory myofibroblastic tumor of liver

Objective To study the multi-slice spiral CT(MSCT)imaging and pathological features of inflammatory myofibroblastic tumor(IMT)of liver.Methods 7 patients with IMT of liver proven by surgery and pathology underwent multi-slice spiral CT examination.The images were reviewed retrospectively and correlated with pathological manifestation.Results Among 7 cases,they were all single mass(5 in right lobe of liver,2 in left lobe).The diameters of masses were different(from 1.7～5.6cm)and 5 cases had ill-defined margin.Although all lesions were hypodense on the precontrast CT scan,they showed variable patterns of contrast enhancement.3 cases showed ring-shaped enhancement,which means that on the arterial phase and portal venous phase scan,non-enhancement or light-enhancement were observed in the central lesions,and ring-shaped enhancement in the peripheral portion of the masses;moreover,liver parenchyma surrounding the masses showed hyperdense(enhancement).3 cases showed nodular enhancement in the mass with central necrosis,which means that on the arterial phase the mass showed nodular enhancement,and further enhancement on the portal venous phase and delayed phase scan with central non-enhancement.1 case showed separate-like enhancement,which means that on the arterial phase,non-enhancement or light-enhancement were observed,and separate-like enhancement in the mass on portal venous or delayed phase scan.Microscopically,the tumors were mainly composed of spindle shaped fibrous cells and inflammatory cells(mainly plasma cell and lymphocyte).Hepatocytes had no manifest heteromorphism.Immunohistochemically,SMA was positive in 4 cases,and Vimentin was positive in 5 cases,and CD68 was positive in 3 cases.Conclusion MSCT provides accurate anatomic location and helpful information for the clinical diagno-sis of IMT of liver,and the definite diagnosis relies on pathological and immunohistochemical study.