Hepatic Angiomyolipoma And Noncirrhotic Hepatocellular Carcinoma: CT/MR Imaging Findings With Pathologic Comparison

Objective The aim of this study was to investigate the computed tomography(CT)and/or magnetic resonance imaging(MRI)findings of hepatic angiomyolipoma(HAML)and non cirrhotic primary hepatocellular carcinoma(HCC),and compare them with pathological findings,to improve the ability of imaging differentiation.Methods Clinical,pathologic,and imaging findings of 18 patients(3 males and 15 females)with HAML and 48 patients with HCC without cirrhosis(39 males and 8 females)pathologically diagnosed and who underwent CT or MRI examinations were retrospectively analyzed.Imaging analysis mainly included tumor diameter,density/signal intensity of lesions,pseudocapsule sign,early drainage vein,intrahepatic metastasis,tumor thrombus and lymph node metastasis.Between-group differences in HAML and HCC were compared by student t test or chi square test where appropriate.Results No cirrhosis was found in all patients with HAML.Pathological examination of HAML showed 11 cases of fat,2 cases of calcification and 1 case of cystic change.Isolated and well-defined masses were the mainly imaging findings of HAML.The average enhancement degree was greater than 120 Hu in 11 cases(61.1%),the peripheral enhancement ring decreased in 15 cases(83.3%)and the early drainage vein occurred in 15 cases(83.3%).All the early drainage veins were hepatic veins without pseudocapsule sign(0%).The blood vessels of tumors were found at the edge or inside the lesions in all patients.The pathological results of HAML demonstrated that the lesions consisted of fat in 11 cases,calcification in 2 cases and cystic change in 1 case.The imaging features of HCC: all tumors showed enhancement mode of "fast in and fast out",39 tumors had pseudocapsule sign(83%),and no early venous drainage(0%).On laboratory test,AFP and PIVKA-Ⅱ elevated in 28 cases(58.3%)and in 30 cases(62.5%),respectively.There were differences in peripheral enhancement ring decreased,early drainage vein,pseudocapsule sign,AFP and PIVKA-Ⅱ between HAML and HCC.Conclusions CT and MR imaging features combined with AFP and abnormal prothrombin(PIVKA-II)are helpful to differentiate HAML from noncirrhotic primary HCC.