Korean J Radiol.  2019 Jul;20(7):1019-1041. 10.3348/kjr.2018.0636.

Atypical Appearance of Hepatocellular Carcinoma and Its Mimickers: How to Solve Challenging Cases Using Gadoxetic Acid-Enhanced Liver Magnetic Resonance Imaging

• Kim JH
• Joo I
• Lee JM

• KMID: 2467020
• DOI: http://doi.org/10.3348/kjr.2018.0636

Abstract

Hepatocellular carcinoma (HCC) can be diagnosed noninvasively with contrast-enhanced dynamic computed tomography, magnetic resonance imaging, or ultrasonography on the basis of its hallmark imaging features of arterial phase hyperenhancement and washout on portal or delayed phase images. However, approximately 40% of HCCs show atypical imaging features, posing a significant diagnostic challenge for radiologists. Another challenge for radiologists in clinical practice is the presentation of many HCC mimickers such as intrahepatic cholangiocarcinoma, combined HCC-cholangiocarcinoma, arterioportal shunt, and hemangioma in the cirrhotic liver. The differentiation of HCCs from these mimickers on preoperative imaging studies is of critical importance. Hence, we will review the typical and atypical imaging features of HCCs and the imaging features of its common mimickers. In addition, we will discuss how to solve these challenges in practice.

Keyword

Atypical hepatocellular carcinoma; Hepatocellular carcinoma mimickers; Intrahepatic mass-forming cholangiocarcinoma; Combined hepatocellular-cholangiocarcinoma; Liver Imaging Reporting and Data System

MeSH Terms

Carcinoma, Hepatocellular*
Cholangiocarcinoma
Hemangioma
Liver*
Magnetic Resonance Imaging*
Ultrasonography

Figure

• 

  Fig. 1 50-year-old man with HCC and hepatitis B-related cirrhosis. (A) T2WI shows hyperintense mass in segment VI of liver. Mass shows hyperenhancement on (B) arterial phase image and definite washout on (C) portal venous and (D) transitional phase images of gadoxetic acid-enhanced liver MRI. Capsule appearance (arrow), internal septum (thin arrows), and mosaic architecture are also noted on portal venous and transitional phase images. (E) Mass is hypointense on HBP image. HBP = hepatobiliary phase, HCC = hepatocellular carcinoma, T2WI = T2-weighted imaging

• 

  Fig. 2 55-year-old man with early HCC and hepatitis B-related cirrhosis. Nodule in segment V of liver is hypointense relative to adjacent liver parenchyma on (A) precontrast T1WI. Nodule shows no definite enhancement on (B) arterial phase image. Nodule is heterogeneous but mostly hypointense on (C) HBP image and isointense on (D) T2WI. Lesion (arrows) shows hyperintensity on (E) DWI (b = 800 sec/mm2) and hypointensity on (F) apparent diffusion coefficient map, suggesting restricted diffusion. DWI = diffusion-weighted imaging, T1WI= T1-weighted imaging

• 

  Fig. 3 52-year-old woman with scirrhous HCC and hepatitis B-related cirrhosis. 4.5-cm mass in segment VI of liver shows rim-like enhancement on (A) arterial phase image and peripheral washout with enhancing capsule (arrow) on (B) delayed phase image. Mass shows hypointensity on (C) HBP image and heterogeneous hyperintensity with central dark area (thin arrows) on (D) T2WI. (E) DWI (b = 800 sec/mm2) shows targetoid appearance characterized by restricted diffusion in periphery and less restricted diffusion in center.

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  Fig. 4 53-year-old man with sarcomatous HCC and hepatitis B-related cirrhosis. A. Arterial phase image of gadoxetic acid-enhanced MRI shows hypovascular mass with peripheral rim-like enhancement (arrow). B. Mass shows progressive centripetal enhancement (arrow) and enhancing septae (thin arrows) on transitional phase image.

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  Fig. 5 Gadoxetic acid-enhanced magnetic resonance images of fibrolamellar HCC in 34-year-old woman without underlying liver disease. A. T2WI shows large, heterogeneous mass with hypointense central scar (thin arrows). (B) Arterial and (C) portal venous phase images show progressive enhancement pattern. D. Mass is mostly hypointense on HBP image.

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  Fig. 6 55-year-old man with infiltrative HCC and B-related cirrhosis. A. T2WI shows infiltrative mass (arrow) in right hepatic lobe with portal vein tumor thrombosis (thin arrow). B. Arterial phase image shows mild enhancement in ill-defined mass (arrow) as well as tumor thrombi (thin arrow). C. Mass (arrow) and tumor thrombi (thin arrow) demonstrate subtle washout on portal venous phase image. (D) HBP and (E) DWIs (b = 1000 sec/mm2) well depict both mass (arrows) and portal vein tumor thrombosis (thin arrows).

• 

  Fig. 7 Intraductal growing HCC in 64-year-old man without underlying liver disease. A. T2WI shows intraductal growing mass (arrow) at proximal bile duct with peripheral intrahepatic bile duct dilatation and ill-defined parenchymal tumor (arrowheads) in right posterior segment of liver. Intraductal lesion (arrows) shows heterogeneous enhancement on (B) arterial phase image and washout on (C) portal venous phase image. Hepatic parenchymal lesion (arrowheads) also shows similar enhancement pattern to intraductal lesion.

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  Fig. 8 59-year-old man with intrahepatic mass-forming cholangiocarcinoma and chronic hepatitis B. (A) T2WI shows hyperintense nodule (arrow) in left lobe of liver. Nodule (arrows) demonstrates definite enhancement on (B) arterial phase image and isointensity on (C) portal venous phase image. D. HBP image demonstrates hypointensity of lesion (arrow).

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  Fig. 9 Intrahepatic mass-forming cholangiocarcinoma in 70-year-old woman without underlying liver disease. In left hepatic lobe, there is large mass with peripheral enhancement (arrow) on (A) arterial phase image and centripetal enhancement on (B) delayed phase image. C. On HBP image, targetoid appearance characterized by marked hypointensity in periphery with mild hypointensity in center is noted. D. On DWI (b = 800 sec/mm2), mass also shows targetoid appearance of central hypointensity with peripheral hyperintensity (arrow).

• 

  Fig. 10 52-year-old man with cHCC-CC and chronic hepatitis B. A. Arterial phase image shows mass with peripheral enhancement (arrow) in segment VII of liver. B. Mass shows centripetal enhancement on transitional phase image. C. Note targetoid appearance on HBP image. Although peripheral rim-like hyperenhancement on arterial phase and targetoid appearance on HBP suggest high probability of non-HCC malignancies such as intrahepatic mass-forming cholangiocarcinoma or cHCC-CC, normal carbohydrate antigen 19-9 and elevated alpha-fetoprotein (289.9 ng/mL) levels suggest high probability of cHCC-CC in this patient. cHCC-CC = combined HCC-cholangiocarcinoma

• 

  Fig. 11 48-year-old woman with hemangioma and chronic hepatitis B. A. Nodule (arrow) shows prominent enhancement on arterial phase image. Note relative hypointensity of nodule (arrows) due to gadoxetic acid uptake by adjacent liver parenchyma on (B) transitional phase image (“pseudo-washout” sign) and dark signal intensity on (C) HBP image. D. T2WI depicts bright signal intensity of lesion (arrow).

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  Fig. 12 Inflammatory HCA in 36-year-old woman without underlying liver disease. A. T2WI shows hyperintense nodule (arrow) in segment VIII of liver. Lesion (arrows) shows prominent enhancement on (B) arterial phase image and iso-signal intensity on (C) portal venous phase image. D. Note relatively low signal intensity of lesion (arrow) on transitional phase image. E. Nodule (arrow) shows low signal intensity on HBP image. On (F) DWI (b = 800 sec/mm2) and (G) apparent diffusion coefficient map, lesion (arrows) shows high signal intensity indicating no restricted diffusion. HCA = hepatocellular adenoma

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  Fig. 13 β-catenin-mutated HCA in 44-year-old man without underlying liver disease. A. T2WI demonstrates large mass (arrows) with intermediate signal intensity in liver. Mass (arrows) shows subtle enhancement on (B) arterial phase image and iso-signal intensity on (C) portal venous phase image. D. Note iso-signal intensity of mass (arrows) on HBP image.

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  Fig. 14 Focal nodular hyperplasia in 45-year-old woman without underlying liver disease. A. T2WI shows slightly hyperintense mass with hyperintense central scar (arrow) in left lobe of liver. B. Mass shows isointensity with hypointense central scar (arrow) on precontrast T1WI. C. Arterial phase image shows prominent enhancement of mass with nonenhancing central scar (arrow). D. Central scar (arrow) shows delayed enhancement on transitional phase image. E. HBP image demonstrates isointense mass with hypointense central scar (arrow).

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  Fig. 15 Hepatic angiomyolipoma in 39-year-old woman without underlying liver disease. A. T2WI shows hyperintense mass in right lobe of liver. Mass shows hyperenhancement on (B) arterial phase image and heterogeneous signal intensity with washout portions (thin arrows) on (C) portal venous phase image. D. Early draining vein (arrow) connecting to right hepatic vein is noted on arterial phase image. E. HBP image shows mass with homogeneous hypointensity, which is lower than signal intensity of spleen (tumor-to-spleen signal intensity ratio: 0.96).

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