Infiltrative hepatocellular carcinoma - tumor extension to the IVC and right atrium

Established liver cirrhosis. The right lobe shows ill-defined heterogeneous mass lesion, initially hypodense with heterogeneous arterial enhancement and washout at portovenous and delayed phases.

Portal vein thrombus at its division extending to both main portal branches partially filling their lumen.

Tumour thrombus is noted filling the right hepatic vein extending to the IVC till the right atrium (right atrial thrombus). It shows enhancement at the arterial phase with washout in theportovenous and delayed phases.

Multiple porta hepatichepatis lymph nodes, one of them showed calcification. Hepatic parenchymal calcifications are also noted.

Recanalised umbilical vein.

The diagnosis, in this case, is based on the imaging features and the clinical data only, however, it is hard to consider other differentials other than hepatocellular carcinoma (HCC). Macrovascular invasion is characteristic of HCC with the HCCinvolvement of the portal vein more common than the hepatic veins. It is a sign of poor prognosis.

IVC and portal vein thrombus are considered tumour thrombus, as they are following the tumour pattern of enhancement and the extension from the tumour itself. The appearance of vessel expansion is also suggestive of tumour thrombus but less specific than arterial enhancement.

Streak and thread appearance of the tumour thrombus is characteristic in angiography and contrast-enhanced CT due to parallel opacification of small vessels and arterial-venous shunting.

Differentiating bland from tumour thrombus is necessary as they have different management and prognosis. Bland thrombus is common in patients with chronic liver disease.