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Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 7, 2020; 26(17): 2012-2029
Published online May 7, 2020. doi: 10.3748/wjg.v26.i17.2012
Pearls and pitfalls in magnetic resonance imaging of hepatocellular carcinoma
Jelena Djokic Kovac, Tamara Milovanovic, Vladimir Dugalic, Igor Dumic
Jelena Djokic Kovac, Departament of Radiology, Clinical Center Serbia, Belgrade 11000, Serbia
Jelena Djokic Kovac, Tamara Milovanovic, Vladimir Dugalic, School of Medicine, Belgrade University, Belgrade 11000, Serbia
Tamara Milovanovic, Departament of Hepatology, Clinical Center Serbia, Belgrade 11000, Serbia
Vladimir Dugalic, Departament of Surgery, Clinical Center Serbia, Belgrade 11000, Serbia
Igor Dumic, Divison of Hospital Medicine, Mayo Clinic College of Medicine and Sciences, Mayo Clinic Health System, New York, NY 10029, United States
Author contributions: Kovac JD wrote the manuscript; Milovanovic T and Dugalic V collected the data; Dumic I contributed data and analysis tools.
Conflict-of-interest statement: The authors declare that they have no conflict of interest.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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/
Corresponding author: Jelena Djokic Kovac, MD, PhD, Professor, Departament of Radiology, Clinical Center Serbia, Pasterova 2, Belgrade 11000, Serbia. jelenadjokickovac@gmail.com
Received: December 31, 2019
Peer-review started: December 31, 2019
First decision: January 13, 2020
Revised: April 20, 2020
Accepted: April 24, 2020
Article in press: April 24, 2020
Published online: May 7, 2020
Processing time: 127 Days and 21 Hours
Abstract

Hepatocellular carcinoma (HCC) is the most common primary hepatic malignancy, which usually arises in cirrhotic liver. When the typical enhancement pattern, consisting of late arterial hyperenhancement followed by washout, is present in nodules larger than 1 cm, HCC can be confidently diagnosed without the need for tissue biopsy. Nevertheless, HCC can display an atypical enhancement pattern, either as iso or hypovascular lesion, or hypervascular lesion without washout. Not only the enhancement pattern of HCC could be atypical, but also a variety of histological types of HCC, such as steatotic, scirrhous, fibrolamellar, or combined hepatocellular-cholangiocellular carcinoma could raise diagnostic dilemmas. In addition, distinct morphological types of HCC or different growth pattern can occur. Awareness of these atypical and rare HCC presentations on magnetic resonance imaging is important for accurate differentiation from other focal liver lesions and timely diagnosis, which allows optimal treatment of patients.

Keywords: Hepatocellular carcinoma; Cirrhosis; Magnetic resonance imaging; Hepatocarcinogenesis

Core tip: The recognition of atypical presentations of hepatocellular carcinoma (HCC) is clinically important, since delay in the diagnosis can lead to inappropriate treatment of the patients. Due to multistep process of hepatocarcinogenesis, atypical vascular enhancement is frequently seen in smaller HCCs. Thus, hypovascular, and hypervascular lesions without washout in cirrhotic liver should raise suspicion of HCC. Additionally, HCC can be present in uncommon morphological patterns, such as diffuse, and infiltrative types. Fibrolamellar, steatotic, scirrhous HCC, and combined cholangiocarcinoma-HCC are rare histological types whose preoperative diagnosis is very challenging. This article reviews tips for differential diagnosis of uncommon HCCs and other liver lesions.