Diffuse hepatocellular carcinoma with malignant portal vein thrombosis and arterioportal shunt
Presentation
History of chronic hepatitis B
Patient Data
The liver shows heterogeneous, marginal irregularity, with multiple parenchymal nodules, in keeping with cirrhosis.
There is an early enhancement of the portal vein, suggestive of an intrahepatic arterioportal shunt. A thrombus occupies the main portal vein and its left and right branches, with hypervascularity suggestive of tumor thrombus.
An ill-defined mass with innumerable nodules in the right hepatic lobe shows heterogeneous arterial enhancement and washout at the portal venous phase. Some hypervascular arterial nodules in the left lobe also show washout at the portal phase.
On the portal venous phase, the tumor can be identified accurately as heterogeneous low density (red star) versus adjacent non-cancerous tissue (green star).
Intrahepatic arterioportal shunt secondary to HCC through the transvasal route 2: on the hepatic arterial phase, the vasa vasorum from the hepatic artery branch passes through the portal vein wall forming a thread-and-streak sign (pink arrow) at the tumor thrombus 1.
Case Discussion
CT findings are consistent with diffuse hepatocellular carcinoma (HCC) with arterioportal shunt and malignant portal vein thrombosis.
The enhancement of HCC will be significantly reduced in the situation of severe arterioportal shunting due to a large amount of contrast medium flowing into the portal vein through the shunt. At the equilibrium phase, the characteristic washout of the tumor can nonetheless be identified accurately. The equilibrium phase is most useful for the diagnosis and delineation of HCC as an area of heterogeneous low density 1.