Editorial
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 28, 2015; 21(32): 9457-9460
Published online Aug 28, 2015. doi: 10.3748/wjg.v21.i32.9457
Contrast-enhanced ultrasound in differentiating malignant from benign portal vein thrombosis in hepatocellular carcinoma
Luciano Tarantino, Pasquale Ambrosino, Matteo Nicola Dario Di Minno
Luciano Tarantino, Department of Surgery, Interventional Hepatology Unit, Andrea Tortora Hospital, 07020 Pagani, Italy
Pasquale Ambrosino, Department of Clinical Medicine and Surgery, Federico II University, 80010 Naples, Italy
Matteo Nicola Dario Di Minno, Unit of Cell and Molecular Biology in Cardiovascular Diseases, Centro Cardiologico Monzino, IRCCS, 20138 Milan, Italy
Author contributions: The three authors equally contributed to the paper.
Conflict-of-interest statement: Di Minno MND has acted as paid lecturer or board member and received grants and honoraria from Bayer, Biotest, Pfizer and Novo-Nordisk in the last 36 mo for researches unrelated to the present study. All the other Authors have nothing to declare.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Matteo Nicola Dario Di Minno, MD, PhD, Unit of Cell and Molecular Biology in Cardiovascular Diseases, Centro Cardiologico Monzino, IRCCS, Via C. Parea 4, 20138 Milan, Italy. dario.diminno@hotmail.it
Telephone: +39-2-58002857 Fax: +39-2-58002857
Received: January 27, 2015
Peer-review started: January 28, 2015
First decision: June 19, 2015
Revised: July 8, 2015
Accepted: July 15, 2015
Article in press: July 15, 2015
Published online: August 28, 2015
Abstract

Portal vein thrombosis (PVT) may occur in liver cirrhosis patients. Malignant PVT is a common complication in cirrhotic patients with concomitant hepatocellular carcinoma (HCC) and, in some cases, it may be even the initial sign of an undetected HCC. Detection of malignant PVT in a patient with liver cirrhosis heavily affects the therapeutic strategy. Gray-scale ultrasound (US) is widely unreliable for differentiating benign and malignant thrombi. Although effective for this differential diagnosis, fine-needle biopsy remains an invasive technique. Sensitivity of color-doppler US in detection of malignant thrombi is highly dependent on the size of the thrombus. Contrast-enhanced computed tomography (CT) and contrast-enhanced magnetic resonance (MRI) can be useful to assess the nature of portal thrombus, while limited data are currently available about the role of positron emission tomography (PET) and PET-CT. In contrast with CT, MRI, PET, and PET-CT, contrast-enhanced ultrasound (CEUS) is a fast, effective, well tolerated and cheap technique, that can be performed even in the same session in which the thrombus has been detected. CEUS can be performed bedside and can be available also in transplanted patients. Moreover, CT and MRI only yield a snapshot analysis during contrast diffusion, while CEUS allows for a continuous real-time imaging of the microcirculation that lasts several minutes, so that the whole arterial phase and the late parenchymal phase of the contrast diffusion can be analyzed continuously by real-time US scanning. Continuous real-time monitoring of contrast diffusion entails an easy detection of thrombus maximum enhancement. Moreover, continuous quantitative analyses of enhancement (wash in - wash out studies) by CEUS during contrast diffusion is nowadays available in most CEUS machines, thus giving a more sophisticated and accurate evaluation of the contrast distribution and an increased confidence in diagnosis in difficult cases. In conclusion, CEUS is a very reliable technique with a high intrinsic sensitivity for portal vein patency assessment. More expensive and sophisticated techniques (i.e., CT, MRI, PET, and PET-CT) should only be indicated in undetermined cases at CEUS.

Keywords: Contrast-enhanced ultrasound, Hepatocellular carcinoma, Portal vein thrombosis, Benign thrombosis, Malignant thrombosis

Core tip: Portal vein thrombosis (PVT) may occur in liver cirrhosis patients. Malignant PVT is a common complication in cirrhotic patients with concomitant hepatocellular carcinoma (HCC) and, in some cases, it may be even the initial sign of an undetected HCC. Due to its high performance in characterization of PVT in cirrhotic patients, contrast-enhanced ultrasound should be considered as the gold standard method and, often, the only diagnostic tool in cirrhotic patients for differential diagnosis between malignant and benign PVT.