CT findings of portal venous tumor thrombosis associated with gastric carcinoma

The objective of this study was to study the CT manifestations of portal venous tumor thrombosis associated with gastric carcinoma. Seven cases clinically and histopathologically proven of portal venous tumor thrombosis associated with gastric carcinoma were studied with CT and the imaging findings were retrospectively analyzed. Each case underwent plain CT, and followed by contrast-enhanced CT with a bolus injection technique. There were no laboratory or imaging findings of cirrhosis in all cases. Metastatic foci in the liver appeared on CT in 3 cases. CT findings with bolus enhancement revealed intraluminal hypodense mass combined with enlarged, sharply defined vessels of main portal vein in all 7 cases, and left and right branches involvement of intrahepatic portal veins in 2 cases, involvement of the superior mesenteric vein in 1 case, involvement of the superior mesenteric vein and splenic vein in another 1 case. The tumor thrombus in five cases of this group demonstrated no evident enhancement while the thrombus in the other 2 cases showed slight enhancement. The portal trunk was greatly dilated due to the tumor thrombus and the blood flow of the portal vein was occluded with some thick tortuous collateral veins visible around the broadened portal trunk in 5 cases while 2 of them were complicated with severe ascites. Although portal venous tumor thrombosis is commonly seen in hepatocellular carcinoma, invasive gastric carcinoma also can be the direct causes of tumor thrombus. The differential diagnosis between these two entities will be easily made with combination of imaging findings and the clinical data.