Presentation
Chronic HCV patient. History of splenectomy.
Patient Data
The liver shows cirrhotic changes manifested by irregular contours and parenchymal dysmorphism. An ill-defined lesion is noted at segment VI (3.4cm); showing heterogeneous postcontrast enhancement, with delayed washout. It shows evident restriction on DWI/ADC consistent with hepatocellular carcinoma (HCC-LR5).
A small enhancing nodule is seen at segment VI/VII interface with mild restriction and no definite wash out (LV4 nodule).
A sizable porta hepatis lymph node is noted measuring about (8 x 7 x 6.8 cm) in average diameters, indenting the medial aspect of the caudate lobe, stretching and displacing the common hepatic artery and portal vein anteriorly. This is associated with other smaller lymph nodes at the right paracaval, aortocaval and para-aortic nodes, ranging in diameter from 2.3 cm to 3.8 cm, consistent with nodal deposits.
Floating bland thrombus in the portal vein extending to the leinorenal collaterals. Left renal vein bland thrombi are also noted with fine extension into the IVC.
Dilated lienorenal collaterals.
The spleen is surgically removed; with small splenule (4.4 cm) is noted at the operative bed.
Both kidneys are normal in size, shape and position. Bilateral cortical renal cysts, the largest on the left side (2.7 cm). No backpressure changes identified.
Case Discussion
Multiple venous thrombi are demonstrated in this case; portal vein thrombus extending to the splenic vein and left renal vein thrombus with fine extension to IVC.
Portal vein thrombus is common in patients with chronic liver disease rather than the tumor thrombus. Differentiating bland from tumor thrombus is necessary as they have different management and prognosis. The presence of malignancy doesn't exclude the possibility of bland thrombus as shown in this case. Also, both can be co-existing.
Bland thrombus is formed due to the change in hemodynamics in veins adjacent to the tumor by the mass effect of the tumor that displaces or compresses these veins.
On imaging, bland thrombus doesn't enhance and separable from the tumor with no signs of tumor vein invasion. The dilated portomesenteric axis, in this case, is due to portal hypertension and less likely an expansion by the thrombus itself which is a sign of a tumor thrombus. Renal vein thrombus is commoner on the left side than the right, presumably as it is longer.
Diffusion-weighted MRI is helpful adjunctive modality with contrast study. Tumor thrombus show restricted diffusion due to high cellularity, unlike bland thrombus. Bland thrombus generally shows non-restricted diffusion. Yet, it may demonstrate low ADC values due to the high viscosity as well as paramagnetic effects of intracellular deoxyhemoglobin and methemoglobin contents 1.