Diagnosis of portal vein thrombosis discontinued with liver tumors in patients with liver cirrhosis and tumors by contrast-enhanced US: A pilot study

Abstract

Aims We assessed the role of contrast-enhanced ultrasound (CEUS) in the differential diagnosis between benign and malignant portal vein thrombosis (PVT) in patients who had liver tumors. Methods Seventeen consecutive patients who had cirrhosis, liver tumors, and PVT were prospectively studied with CEUS. CEUS was performed at low mechanical index after intravenous administration of a second-generation contrast agent (SonoVue, Bracco, Milan, Italy). Presence or absence of thrombus enhancement on CEUS were considered diagnostic for malignant or benign PVT. Five patients also underwent percutaneous portal vein fine-needle biopsy under US guidance. All patients were followed-up. Shrinkage of the thrombus and/or recanalization of the vessels on CDUS during follow-up were considered definitive evidence of the benign nature of the thrombosis, whereas the enlargement of the thrombus, disruption of the vessel wall, and parenchymal infiltration over follow-up were considered consistent with malignancy. Results Follow-up showed signs of malignant thrombosis in 14 of 17 patients. CEUS showed early arterial enhancement of the PVT in 14 patients of 14 malignant PVT, 1 patient of 3 benign PVT and the absence of thrombus enhancement in 2 patients of 3 benign PVT. FNB confirmed the results for malignant PVT in four of five patients, for benign granulomatous inflammation PVT in one of five patients in which CEUS showed early arterial enhancement of the PVT. The sensitivity, specificity and accuracy is 100%, 66.7% and 93.3% at diagnosis of malignant PVT using CEUS. In one patient with intrahepatic bile duct stone, CEUS were positive for malignant PVT, whereas FNB was negative (benign granulomatous inflammation PVT); follow-up examination confirmed benign PVT. Conclusion CEUS seems to be the pretty sensitive and specific test for diagnosing malignant portal vein thrombosis in patients with cirrhosis and tumors.