Clinicopathological investigation of steatohepatitic hepatocellular carcinoma: A multicenter study using immunohistochemical analysis of adenoma-related markers

Diffuse and focal liver fat: advanced imaging techniques and diagnostic insights

The fatty liver disease represents a complex, multifaceted challenge, requiring a multidisciplinary approach for effective management and research. This article uses conventional and advanced imaging techniques to explore the etiology, imaging patterns, and quantification methods of hepatic steatosis. Particular emphasis is placed on the challenges and advancements in the imaging diagnostics of fatty liver disease. Techniques such as ultrasound, CT, MRI, and elastography are indispensable for providing deep insights into the liver's fat content. These modalities not only distinguish between diffuse and focal steatosis but also help identify accompanying conditions, such as inflammation and fibrosis, which are critical for accurate diagnosis and management.

Imaging and prognostic characterization of fat-containing hepatocellular carcinoma subtypes

PURPOSE

Steatohepatitic hepatocellular carcinoma (SH-HCC) is characterized by intratumoral fat with > 50% inflammatory changes. However, intratumoral fat (with or without inflammation) can also be found in not-otherwise specified HCC (NOS-HCC). We compared the imaging features and outcome of resected HCC containing fat on pathology including SH-HCC (> 50% steatohepatitic component), NOS-HCC with < 50% steatohepatitic component (SH-NOS-HCC), and fatty NOS-HCC (no steatohepatitic component).

MATERIAL AND METHODS

From September 2012 to June 2021, 94 patients underwent hepatic resection for fat-containing HCC on pathology. Imaging features and categories were assessed using LIRADS v2018. Fat quantification was performed on chemical-shift MRI. Recurrence-free and overall survival were estimated.

RESULTS

Twenty-one patients (26%) had nonalcoholic steatohepatitis (NASH). The median intra-tumoral fat fraction was 8%, with differences between SH-HCC and SH-NOS-HCC (9.5% vs. 5% p = 0.03). There was no difference in major LI-RADS features between all groups; most tumors were classified as LR-4/5. A mosaic architecture on MRI was rare (7%) in SH-HCC, a fat in mass on CT was more frequently depicted (48%) in SH-HCC. A combination of NASH with no mosaic architecture on MRI or NASH with fat in mass on CT yielded excellent specificity for diagnosing SH-HCC (97.6% and 97.7%, respectively). The median recurrence-free and overall survival were 58 and 87 months, with no difference between groups (p = 0.18 and p = 0.69).

CONCLUSION

In patients with NASH, an SH-HCC may be suspected in L4/LR-5 observations with no mosaic architecture at MRI or with fat in mass on CT. Oncological outcomes appear similar between fat-containing HCC subtypes.

Fat-containing hepatocellular carcinoma in patients with cirrhosis: proposal of a diagnostic modification regarding enhancement characteristics

OBJECTIVES

The aim of this study was to develop and validate an algorithm for the non-invasive diagnosis of these fat-containing HCCs.

METHODS

Eighty-four cirrhotic patients with 77 fat-containing HCCs and 11 non-HCC fat-containing nodules were retrospectively included. All MRIs were reviewed; nodule characteristics, European Association for the Study of the Liver (EASL) and LI-RADS classifications, and survival were collected. One of the major features of LI-RADS v2018 (non-rim-like arterial phase hyperenhancement [APHE]) was changed to include different enhancing patterns at arterial phase and a new fat-LI-RADS algorithm was created for fat-containing nodules in cirrhosis. Its diagnostic performance was evaluated in both a derivation and external validation cohort (external cohort including 58 fat-containing HCCs and 10 non-HCC fat nodules). Reproducibility of this new algorithm was assessed.

RESULTS

In the derivation cohort, 54/77 (70.1%) fat-containing HCCs had APHE, 62/77 (80.5%) had enhancement compared to the nodule itself at arterial phase (APE), 43/77 (55.8%) had washout, and 20/77 (26.0%) had an enhancing capsule. EASL and LI-RADS had a sensitivity of 37.7% (29/77) and 36.4% (28/77), respectively, for the diagnosis of fat-containing HCC and both had a specificity of 100% (11/11). The new fat-LI-RADS algorithm increased sensitivity to 50.6% (39/77) without decreasing the specificity of 100% (11/11). The validation cohort confirmed the increased sensitivity, with a slight decrease in specificity. The concordance for the diagnosis of HCC for fat-LR5 was 85.3% (58/68).

CONCLUSION

The new fat-LI-RADS algorithm proposed here significantly improves the performance of the non-invasive diagnosis of fat-containing HCC and thus could reduce the number of biopsies conducted for fat-containing HCCs.

CLINICAL RELEVANCE STATEMENT

The European Association for the Study of the Liver and LI-RADS guidelines are poorly sensitive for the diagnosis of fat-containing HCC, mainly because of the low rate of arterial phase hyperenhancement (APHE) displayed by fat-containing HCC. Using all types of enhancement instead of APHE improves sensitivity of LI-RADS.

KEY POINTS

• Fat-containing HCCs on MRI account for 7.5% of HCCs and have different imaging characteristics from non-fatty HCCs. • The European Association for the Study of the Liver and LI-RADS algorithms for the non-invasive diagnosis of HCC have low sensitivity for the diagnosis of fat-containing HCC with MRI (37.7% and 36.4%, respectively). • The new fat-LI-RADS, which includes a slight modification of the "arterial enhancement" criterion, improves the sensitivity for the diagnosis of fat-containing HCC using MRI, without degrading the specificity.

Fat fraction and R2 * values of various liver masses: Initial experience with 6-point Dixon method on a 3T MRI system

Purpose

To assess the feasibility of the 6-point Dixon method for evaluating liver masses. We also report our initial experience with the quantitative values in various liver masses on a 3T system.

Materials and methods

Of 251 consecutive patients for whom 6-point Dixon was employed in abdominal magnetic resonance imaging scans between October 2020 and October 2021, 117 nodules in 117 patients with a mass diameter of more than 1 cm were included in the study. Images for measuring the proton density fat fraction (PDFF) and R2 * values were obtained using the iterative decomposition of water and fat with echo asymmetry and least-squares estimation-quantitative technique for liver imaging. Two radiologists independently measured PDFF (%) and R2 * (Hz). Inter-reader agreement and the differences between readers were examined using intra-class correlation coefficient (ICC) and the Bland-Altman method, respectively. PDFF and R2 * values in differentiating liver masses were examined.

Results

The masses included hepatocellular carcinoma (n = 59), cyst (n = 20), metastasis (n = 14), hemangioma (n = 8), and others (n = 16). The ICCs for the region of interest (mm2), PDFF, and R2 * were 0.988 (95 % confidence interval (CI): 0.983, 0.992), 0.964 (95 % CI: 0.949, 0.975), and 0.962 (95 % CI: 0.941, 0.975), respectively. The differences of measurements between the readers showed that 5.1 % (6/117) and 6.0% (7/117) for PDFF and R2 * , respectively, were outside the 95 % CI.

Conclusion

Our observation indicates that the 6-point Dixon method is applicable to liver masses.

Pathology and Pathogenesis of Metabolic Dysfunction-Associated Steatotic Liver Disease-Associated Hepatic Tumors

Nonalcoholic fatty liver disease (NAFLD) is characterized by excessive fat accumulation in the livers of patients without a history of alcohol abuse. It is classified as either simple steatosis (nonalcoholic fatty liver) or nonalcoholic steatohepatitis (NASH), which can progress to liver cirrhosis and hepatocellular carcinoma (HCC). Recently, it was suggested that the terms "metabolic dysfunction-associated steatotic liver disease (MASLD)" and "metabolic dysfunction-associated steatohepatitis (MASH)" should replace the terms "nonalcoholic fatty liver disease (NAFLD)" and "nonalcoholic steatohepatitis (NASH)", respectively, with small changes in the definitions. MASLD, a hepatic manifestation of metabolic syndrome, is rapidly increasing in incidence globally, and is becoming an increasingly important cause of HCC. Steatohepatitic HCC, a histological variant of HCC, is characterized by its morphological features resembling non-neoplastic steatohepatitis and is closely associated with underlying steatohepatitis and metabolic syndrome. Variations in genes including patatin-like phospholipase domain-containing protein 3 (PNPLA3), transmembrane 6 superfamily 2 (TM6SF2), and membrane-bound O-acyltransferase domain-containing protein 7 (MBOAT7) are associated with the natural history of MASLD, including HCC development. The mechanisms of HCC development in MASLD have not been fully elucidated; however, various factors, including lipotoxicity, inflammation, reactive oxygen species, insulin resistance, and alterations in the gut bacterial flora, are important in the pathogenesis of MASLD-associated HCC. Obesity and MASLD are also recognized as risk factors for hepatocellular adenomas, and recent meta-analyses have shown an association between MASLD and intrahepatic cholangiocarcinoma. In this review, we outline the pathology and pathogenesis of MASLD-associated liver tumors.

Pathological overview of steatohepatitic hepatocellular carcinoma in a surgical series

AIMS

According to the last WHO classification, steatohepatitic hepatocellular carcinoma (SH-HCC) is recognized as a distinct HCC subtype, even though a consensual definition is still lacking. The objectives of the study were to carefully describe the morphological features of SH-HCC and evaluate its impact on prognosis.

METHODS AND RESULTS

We conducted a single-centre retrospective study including 297 surgically resected HCC. Pathological features including SH criteria (steatosis, ballooning, Mallory-Denk bodies, fibrosis, and inflammation) were assessed. SH-HCC was defined by the presence of at least four of the five SH criteria and the SH component represented >50% of the tumour area. According to this definition, 39 (13%) HCC cases corresponded to SH-HCC and 30 cases (10%) corresponded to HCC with an SH component (<50%). SH criteria in SH-HCC and non-SH-HCC were distributed as follows: ballooning (100% versus 11%), fibrosis (100% versus 81%), inflammation (100% versus 67%), steatosis (92% versus 8%), and Mallory-Denk bodies (74% versus 3%). Inflammation markers (c-reactive protein [CRP] and serum amyloid A [SAA]) were significantly more expressed in SH-HCC compared to non-SH-HCC (82% versus 14%, P = <0.001). Five-year recurrence-free survival (RFS) and 5-year overall survival (OS) were similar for SH-HCC and non-SH-HCC (P = 0.413 and P = 0.866, respectively). The percentage of SH component does not impact OS and RFS.

CONCLUSION

We confirm in a large cohort the relatively high prevalence (13%) of SH-HCC. Ballooning is the most specific criteria for this subtype. The percentage of the SH component does not impact prognosis.

Contrast-Enhanced Imaging Features and Clinicopathological Investigation of Steatohepatitic Hepatocellular Carcinoma

Steatohepatitic hepatocellular carcinoma (SH-HCC) is a distinctive histologic variant of HCC for the presence of steatohepatitis. This study intended to evaluate the contrast-enhanced imaging features and clinicopathological characteristics of 26 SH-HCCs in comparison with 26 age-and-sex-matched non-SH-HCCs. The frequency of obesity (34.6%, p = 0.048) and type 2 diabetes mellitus (23.1%, p = 0.042) were significantly higher in SH-HCC patients. As seen via B-mode ultrasound (BMUS), SH-HCCs were predominantly hyperechoic (65.4%, p = 0.002) lesions, while non-SH-HCCs were mainly hypo-echoic. As seen via contrast-enhanced ultrasound (CEUS), 96.2% of SH-HCCs exhibited hyperenhancement in the arterial phase. During the portal venous and late phase, 88.5% of SH-HCCs showed late and mild washout. Consequently, most SH-HCCs and all non-SH-HCCs were categorized as LR-4 or LR-5. As seen via magnetic resonance imaging (MRI), a signal drop in the T1WI opposed-phase was observed in 84.6% of SH-HCCs (p = 0.000). Notably, diffuse fat in mass was detected in 57.7% (15/26) SH-HCCs (p < 0.001). As seen via contrast-enhanced MRI (CEMRI), most of the SH-HCCs and non-SH-HCCs exhibited heterogeneous hyperenhancement in the arterial phase (80.8% versus 69.2%, p = 0.337). During the delayed phase, 76.9% SH-HCCs and 88.5% non-SH-HCCs exhibited hypo-enhancement. Histopathologically, the rate of microvascular invasion (MVI) was significantly lower in SH-HCCs than non-SH-HCCs (42.3% versus 73.1%, p = 0.025). The frequency of hepatic steatosis >5% in non-tumoral liver parenchyma of SH-HCCs was significantly higher than in non-SH-HCCs (88.5% versus 26.9%, p = 0.000). Additionally, the fibrotic stages of S0, S1 and S2 in SH-HCCs were significantly higher than in non-SH-HCCs (p = 0.044). During follow-up, although the PFS of SH-HCC patients was significantly longer than non-SH-HCC patients (p = 0.046), for the overall survival rate of SH-HCC and non-SH-HCC patients there was no significant difference (p = 0.162). In conclusion, the frequency of metabolism-related diseases in SH-HCC patients was significantly higher than in non-SH-HCC patients. The imaging features of SH-HCCs combined the fatty change and typical enhancement performance of standard HCC as seen via CEUS/CEMRI.

Hepatocellular carcinoma in non-alcoholic steatohepatitis without cirrhosis

Cirrhosis is an emerging major cause of the development of hepatocellular carcinoma (HCC), but in non-alcoholic fatty liver disease (NAFLD), up to 50% of patients with HCC had no clinical or histological evidence of cirrhosis. It is currently challenging to propose general recommendations for screening patients with NAFLD without cirrhosis, and each patient should be evaluated on a case-by-case basis based on the profile of specific risk factors identified. For HCC screening in NAFLD, a valid precision-based screening is needed. Currently, when evaluating this population of patients, the use of non-invasive methods can guide the selection of those who should undergo a screening and surveillance program. Hence, the objective of the present study is to review the epidemiology, the pathophysiology, the histopathological aspects, the current recommendations, and novel perspectives in the surveillance of non-cirrhotic NAFLD-related HCC.

Clinicopathological assessment of steatohepatitic hepatocellular carcinoma

AIM

To compare the clinicopathological features of typical steatohepatitic HCC (SH-HCC) with other HCCs.

METHODS

Subjects were 486 patients with untreated HCC who underwent hepatectomy at our hospital from January 2015 to December 2020. We compared patient backgrounds, preoperative laboratory data, imaging findings (ultrasonography, computed tomography [CT], and magnetic resonance imaging [MRI]), and postoperative pathological findings (tumor and background of liver). The Liver Imaging Reporting And Data System (LI-RADS) was used to examine CT and MRI findings.

RESULTS

Typical SH-HCCs were significantly different from other HCCs with respect to age, hepatitis B virus (HBV) infection, and nonalcoholic steatohepatitis (NASH). Diabetes and hyperlipidemia were also significantly more common. Regarding histopathology, tumor size and background steatosis were significantly different between groups. Although ultrasonography, CT, and MRI could each alone diagnose SH-HCCs with a diameter < 20 mm in ≥ 50% of patients, the combined use of these tests improved diagnostic accuracy. By LI-RADS, 87% of SH-HCC cases were classified as LR-5, which are considered to be malignant tumors.

CONCLUSIONS

It seems possible to diagnose SH-HCC by combining ultrasonography, CT, and MRI.

Correlation of molecular alterations with pathological features in hepatocellular carcinoma: Literature review and experience of an Italian center

Hepatocellular carcinoma (HCC) represents the primary carcinoma of the liver and the fourth leading cause of cancer-related deaths. The World Health Organization estimates an increase in cases in the coming years. The risk factors of HCC are multiple, and the incidence in different countries is closely related to the different risk factors to which the population is exposed. The molecular mechanisms that drive HCC tumorigenesis are extremely complex, but understanding this multistep process is essential for the identification of diagnostic, prognostic, and therapeutic markers. The development of multigenic next-generation sequencing panels through the parallel analysis of multiple markers can provide a landscape of the genomic status of the tumor. Considering the literature and our preliminary data based on 36 HCCs, the most frequently altered genes in HCCs are TERT, CTNNB1, and TP53. Over the years, many groups have attempted to classify HCCs on a molecular basis, but a univocal classification has never been achieved. Nevertheless, statistically significant correlations have been found in HCCs between the molecular signature and morphologic features, and this leads us to think that it would be desirable to integrate the approach between anatomic pathology and molecular laboratories.

Diagnostic Value of Multislice Spiral Computed Tomography Combined with Serum AFP, TSGF, and GP73 Assay in the Diagnosis of Primary Liver Cancer

Objective

To explore the diagnostic value of multislice spiral computed tomography (MSCT) scan combined with serum alpha-fetoprotein (AFP), tumor-specific growth factor (TSGF), and Golgi protein73 (GP73) assays in the diagnosis of primary liver cancer (PLC).

Methods

Totally, 60 patients with PLC admitted to The Second Hospital of Dalian Medical University from January 2019 to January 2020 were included in group A, 60 patients with liver cirrhosis were included in group B, and 60 healthy subjects were included in group C. The serum AFP, TSGF, and GP73 levels were determined, and all participants received MSCT scanning. The diagnostic efficacy of MSCT, assays of serum AFP, TSGF, and GP73, and their combined detection was analyzed.

Results

Group A had the highest levels of AFP, TSGF, and GP73, followed by group B, and then group C. The sensitivity, specificity, positive predictive value, and negative predictive value of MSCT for PLC were 80.0%,91.7%, 82.8%, and 90.2%, respectively, while those of combined detection of MSCT plus serum AFP, TSGF, and GP73 for PLC were 100.0%, 93.3%, 88.2%, and 100.0%. The combined detection was associated with significantly a higher detection rate of PLC versus stand-alone detection.

Conclusion

MSCT plus serum AFP, TSGF, and GP73 has a higher detection rate versus stand-alone detection, which shows great potential in the diagnosis of PLC.

Discrepancy of contrast-enhanced ultrasonographic pattern with two contrast agents in steatohepatitic subtype hepatocellular carcinoma: A case report

Contrast-enhanced ultrasound (CEUS) is one of the important imaging modalities for diagnosis of hepatocellular carcinoma (HCC). Sonovue and Sonazoid are the third-generation of ultrasound contrast agents that have been commercialized and widely used in clinical applications. This study introduces the imaging differences between these two agents in vascular phases for the first time. A 54-year-old man clinical suspected liver cancer. He had chronic hepatitis B for more than 20 years. The result of alpha-fetoprotein was 36.45μg/L (normal< 20μg/L). The imaging pattern of CEUS with Sonovue was “fast-in and fast-out” performance, while the pattern of “fast-out” was absent after portal phase with Sonazoid, even in Kupffer phase. The lesion was diagnosed as lipid-rich HCC by contrast-enhanced MRI. After liver resection, pathology revealed that it was hepatocellular carcinoma contained poor-differentiated steatohepatitis subtype and moderate-differentiated microtrabecular subtype. The imaging difference mainly existed in the part of steatohepatitis subtype. Steatohepatitis subtype HCC can be showed as “fast-in and no wash-out” characteristic in Sonazoid CEUS. Though the mechanism remains not fully clarified, this different enhancing pattern may provide a potential for the supplement of the guidelines and differential of steatohepatitis subtype HCC.

Imaging features of histological subtypes of hepatocellular carcinoma: Implication for LI-RADS

Background & Aims

The histopathological subtypes of hepatocellular carcinoma (HCC) are associated with distinct clinical features and prognoses. This study aims to report Liver Imaging Reporting and Data System (LI-RADS)-defined imaging features of different HCC subtypes in a cohort of resected tumours and to assess the influence of HCC subtypes on computed tomography (CT)/magnetic resonance imaging (MRI) LI-RADS categorisation in the subgroup of high-risk patients.

Methods

This retrospective institutional review board-approved study included patients with resected HCCs and available histopathological classification. Three radiologists independently reviewed preoperative CT and MRI exams. The readers evaluated the presence of imaging features according to LI-RADS v2018 definitions and provided a LI-RADS category in patients at high risk of HCC. Differences in LI-RADS features and categorisations were assessed for not otherwise specified (NOS-HCC), steatohepatitic (SH-HCC), and macrotrabecular-massive (MTM-HCC) types of HCCs.

Results

Two hundred and seventy-seven patients (median age 64.0 years, 215 [77.6%] men) were analysed, which involved 295 HCCs. There were 197 (66.7%) NOS-HCCs, 62 (21.0%) SH-HCCs, 23 (7.8%) MTM-HCCs, and 13 (4.5%) other rare subtypes. The following features were more frequent in MTM-HCC: elevated α-foetoprotein serum levels (p <0.001), tumour-in-vein (p <0.001 on CT, p ≤0.052 on MRI), presence of at least 1 LR-M feature (p ≤0.010 on CT), infiltrative appearance (p ≤0.032 on CT), necrosis or severe ischaemia (p ≤0.038 on CT), and larger size (p ≤0.006 on CT, p ≤0.011 on MRI). SH-HCC was associated with fat in mass (p <0.001 on CT, p ≤0.002 on MRI). The distribution of the LI-RADS major features and categories in high-risk patients did not significantly differ among the 3 main HCC subtypes.

Conclusions

The distribution of LI-RADS major features and categories is not different among the HCC subtypes. Nevertheless, careful analysis of tumour-in-vein, LR-M, and ancillary features as well as clinico-biological data can provide information for the non-invasive diagnosis of HCC subtypes.

Lay summary

In high-risk patients, the overall distribution of LI-RADS major features and categories is not different among the histological subtypes of hepatocellular carcinoma, but tumour-in-vein, presence of LR-M features, and ancillary features can provide information for the non-invasive diagnosis of hepatocellular carcinoma subtypes.

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The distribution of the major features and categories of LI-RADS is not different among the HCC histological subtypes.

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MTM-HCC was associated with TIV, ≥1 LR-M feature, infiltrative appearance, necrosis or severe ischaemia, and larger size.

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Steatohepatitis-related HCC was associated with fat in mass on CT and on MRI.

Steatotic and Steatohepatitic Hepatocellular Carcinomas: Features in a Series With Predominantly Viral Etiology

Hepatocellular carcinomas (HCCs) with steatohepatitis and steatosis are reported with varying definitions and clinicopathologic features. We aimed to search the attributes of steatohepatitic hepatocellular carcinoma (SH-HCC) and steatotic-HCC in our series. A retrospective clinicopathologic analyses of 150 HCCs and immunostaining for C-reactive protein (CRP) and serum amyloid A (SAA) were performed. Tumors were reclassified as all SH-HCC, limited SH-HCC, typical SH-HCC (steatohepatitic features in >5%, 5% to 50%, and ≥50% of the tumor, respectively), steatotic-HCC, and classic HCC (C-HCC). Group comparisons were made using Kruskal-Wallis and Kaplan-Meier tests. The background etiology in all SH-HCCs was pure viral in 51.4%, nonalcoholic steatohepatitis (NASH)/alcoholic liver disease (ALD) alone/mixed in 34.3%, and unidentified in normal liver in 14.3%. All SH-HCCS (n=35, 23.3%) and typical SH-HCCs (n=13, 8.6%) had higher NASH/ALD. Limited SH-HCCs (n=22, 14.6%) had higher ALD (all P<0.05). Typical SH-HCCs tended to have more NASH (P=0.054). Steatotic-HCCs (n=13, 9%) and C-HCCs (n=102, 68%) had higher pure viral etiology and serum CRP (all P<0.05). CRP and SAA were positive in 69% and 27% of the tumors, respectively. SAA positivity correlated with ALD (P=0.026). In the overall group disease-free survival rates at 1, 5, 10, and 20 years were 97.0%, 82.3%, 79.6%, and 77.2%, respectively. Demographics, tumor characteristics, CRP and SAA positivity, and survival were similar between the groups (P>0.05). SH-HCC is heterogenous in terms of underlying etiologies, and can be seen in NASH/ALD, pure viral and noncirrhotic/normal background. The ≥50% cutoff for the definition of SH-HCC can lead to overlook ALD-related SH-HCC. Steatotic-HCC seems more similar to C-HCC rather than SH-HCC, but none of them feature as a different prognostic group.

Decoding Genes: Current Update on Radiogenomics of Select Abdominal Malignancies

Technologic advances in chromosomal analysis and DNA sequencing have enabled genome-wide analysis of cancer cells, yielding considerable data on the genetic basis of malignancies. Evolving knowledge of tumor genetics and oncologic pathways has led to a better understanding of histopathologic features, tumor classification, tumor biologic characteristics, and imaging findings and discovery of targeted therapeutic agents. Radiogenomics is a rapidly evolving field of imaging research aimed at correlating imaging features with gene mutations and gene expression patterns, and it may provide surrogate imaging biomarkers that may supplant genetic tests and be used to predict treatment response and prognosis and guide personalized treatment options. Multidetector CT, multiparametric MRI, and PET with use of multiple radiotracers are some of the imaging techniques commonly used to assess radiogenomic associations. Select abdominal malignancies demonstrate characteristic imaging features that correspond to gene mutations. Recent advances have enabled us to understand the genetics of steatotic and nonsteatotic hepatocellular adenomas, a plethora of morphologic-molecular subtypes of hepatic malignancies, a variety of clear cell and non-clear cell renal cell carcinomas, a myriad of hereditary and sporadic exocrine and neuroendocrine tumors of the pancreas, and the development of targeted therapeutic agents for gastrointestinal stromal tumors based on characteristic KIT gene mutations. Mutations associated with aggressive phenotypes of these malignancies can sometimes be predicted on the basis of their imaging characteristics. Radiologists should be familiar with the genetics and pathogenesis of common cancers that have associated imaging biomarkers, which can help them be integral members of the cancer management team and guide clinicians and pathologists. Online supplemental material is available for this article. ^©RSNA, 2020 See discussion on this article by Luna (pp 1627-1630).

New Names for Old Tumors

OBJECTIVES

Previous studies described "clear cell" hepatocellular carcinoma (HCC), although definitions have varied. New clear cell subtypes of HCC have been proposed, including chromophobe (C-HCC), steatohepatitic (SH-HCC), and steatotic (S-HCC), and this study assessed the utility and clinical-pathologic profile of these subtypes.

METHODS

Current histologic definitions, including 3 separate proposed definitions for SH-HCC, were applied to tumors previously characterized as clear cell HCC. Histologic and clinical variables were analyzed.

RESULTS

Of 66 HCCs, 51 (77%) were classified using modern definitions, including 34 SH-HCCs, 15 S-HCCs, and 2 C-HCCs. Compared with the most permissive SH-HCC definition, the other 2 definitions designated 30 and 25 SH-HCCs (-12% and -26% cases, respectively). Unsurprisingly, S-HCC and SH-HCC were associated with steatotic clear cells (P < .0001). S-HCC was also more typically early type and low grade (P = .0017). The remaining unclassified clear cell HCCs were associated with flocculent (rather than steatotic or optically clear) cytoplasm (P < .0001) but otherwise demonstrated no discrete clinical-pathologic profile.

CONCLUSIONS

Current definitions could be used to reclassify the majority of "clear cell" HCCs. The subtypes are significantly correlated with a few variables, suggesting valid differences of the subtypes, although additional study is warranted, particularly to standardize the definition of SH-HCC.

Small Steatotic HCC: A Radiological Variant Associated With Improved Outcome After Ablation

Percutaneous thermal ablation is a validated treatment option for small hepatocellular carcinoma (HCC). Steatotic HCC can be reliably detected by magnetic resonance imaging. To determine the clinical relevance of this radiological variant, we included 235 patients (cirrhosis in 92.3%, classified Child-Pugh A in 97%) from a prospective database on percutaneous thermal ablation for <3 cm HCC. Among these patients, 52 (22.1%) had at least one steatotic HCC nodule. Nonalcoholic steatohepatitis was more frequent in patients with than without steatotic HCC (P = 0.057), whereas body mass index, diabetes mellitus, liver steatosis, and liver fat content did not differ between groups. Liver disease was less advanced in patients with than without steatotic HCC: lower total bilirubin ( - 2.1 µmol/L; P = 0.035), higher albumin (+0.8 g/L; P = 0.035), and lower Model for End-Stage Liver Disease score (-0.8; P = 0.014). Tumor phenotype was less aggressive in patients with steatotic HCC: lower alpha-fetoprotein (AFP) concentration (P = 0.019), less frequent AFP > 100 ng/mL (P = 0.045), and multifocality (P = 0.015). During the follow-up (median: 28.3 months), overall mortality (3.8% vs. 23.5%; P = 0.001) and HCC-specific mortality (0.0% vs. 14.2%; P = 0.002) rates were lower in patients with steatotic HCC. Early (<2 years) recurrence was also less frequent (32.7% vs. 49.2%; P = 0.041). The mean time to intrahepatic distant recurrence (16.4 vs. 9 months, P = 0.006) and the median time to recurrence and recurrence-free survival (32.4 vs. 18.6 months, P = 0.024 and 30.4 vs. 16.4 months, P = 0.018) were longer in patients with steatotic versus nonsteatotic HCC. The 3-year overall survival was 94.4% and 70.9% in steatotic and nonsteatotic HCC (P = 0.008). In multivariate analysis, steatotic HCC (hazard ratio = 0.12; P = 0.039) and AFP (HR=1.002; P < 0.001) independently predicted overall survival. Conclusion: Small steatotic HCC detected by magnetic resonance imaging is associated with a less aggressive tumor phenotype. In patients with such radiological variant, percutaneous thermal ablation results in improved outcome.

The Current View of Nonalcoholic Fatty Liver Disease-Related Hepatocellular Carcinoma

Simple Summary

The incidence of nonalcoholic fatty liver disease (NAFLD)-related hepatocellular carcinoma (HCC) is increasing. However, an effective screening or surveillance method is not established. Recently, the NAFLD/nonalcoholic steatohepatitis (NASH) guidelines of Japan were revised to incorporate new strategies and evidence for the management and surveillance of NAFLD/NASH. Advanced fibrosis and lifestyle-related and metabolic comorbidities, especially obesity and diabetes mellitus, are associated with HCC development. At the first screening, serum markers of hepatic fibrosis (hyaluronic acid, type IV collagen 7S, and mac-2 binding protein), or the fibrosis (FIB)-4 index or the nonalcoholic fatty liver disease fibrosis score (NFS), or a platelet count should be evaluated. When liver fibrosis is indicated, consultation with a gastroenterology specialist should be considered for the second screening. The risk of HCC should be stratified using the FIB-4 index or the NFS. Liver stiffness should be measured using vibration-controlled transient elastography in those at intermediate or high risk. Blood tests and imaging should be performed every 6–12 months in patients with advanced fibrosis for HCC surveillance. We review here what is known about NAFLD-HCC and provide perspectives for future research.

Abstract

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome and can develop into hepatocellular carcinoma (HCC). The incidence of NAFLD-related HCC, which is accompanied by life-threatening complications, is increasing. Advanced fibrosis and lifestyle-related and metabolic comorbidities, especially obesity and diabetes mellitus, are associated with HCC development. However, HCC is also observed in the non-cirrhotic liver. Often, diagnosis is delayed until the tumor is relatively large and the disease is advanced; an effective screening or surveillance method is urgently required. Recently, the NAFLD/nonalcoholic steatohepatitis (NASH) guidelines of Japan were revised to incorporate new strategies and evidence for the management and surveillance of NAFLD/NASH. Fibrosis must be tested for noninvasively, and the risk of carcinogenesis must be stratified. The treatment of lifestyle-related diseases is expected to reduce the incidence of NAFLD and prevent liver carcinogenesis.

Steatohepatitic hepatocellular carcinoma: imaging findings with clinicopathological correlation

AIM

To evaluate the clinicopathological and computed tomography (CT) and magnetic resonance imaging (MRI) findings of steatohepatitic hepatocellular carcinoma (SH-HCC).

MATERIALS AND METHODS

Clinicopathological and radiological features were evaluated in 20 patients with SH-HCC. The diagnosis of SH-HCC was made histologically if the tumour had four of the following five characteristics: steatosis (>5% tumour cells), ballooning, Mallory-Denk bodies, interstitial fibrosis, and inflammation. All patients underwent dynamic CT and MRI. CT and MRI images were reviewed for morphological features including tumour size, presence, and distribution of fat, and patterns and degree of contrast enhancement.

RESULTS

Obesity, hypertension, and history of heavy alcohol intake were common clinical findings observed in 10 (50%), 13 (65%), and 11 (55%) of the 20 patients, respectively. Steatosis and steatohepatitis were pronounced in the background liver in 12 (60%) and 10 (50%) patients, respectively. SH-HCC was moderately differentiated in 18 patients (90%) and well differentiated in two (10%). Pathologically, steatohepatitic features were diffuse in 12 (60%) of the 20 tumours and focal in eight (40%). Tumour size and the percentage of intratumoural steatosis were not correlated (r=0.17, p=0.47). On CT, 16 (80%) patients showed arterial phase enhancement and delayed washout. On MRI, 16 (80%) of 20 tumours showed prominent fatty deposition (10 diffusely, six focally) with arterial phase enhancement.

CONCLUSIONS

SH-HCC is likely to show prominent fatty deposits with arterial phase enhancement on CT and MRI. A hypervascular lesion with prominent fatty change should raise the diagnostic suspicion of SH-HCC.

A case of hemorrhage of hepatocellular carcinoma resembling a hepatic cyst arising from non-cirrhotic steatohepatitis

A 70-year-old female was found to have multiple hepatic cysts at her annual checkup. In the posterior segment of the right lobe of the liver, an 81 × 67 mm circular cystic lesion was detected by contrast-enhanced computed tomography (CT). Magnetic resonance imaging (MRI) of the cyst revealed a solid component. The cyst had a capsule-like structure and non-uniform fluid accumulation suggested bleeding. Since the lesion was enlarged and malignancy could not be ruled out, it was surgically resected. Histopathologically, reticular fibers of the liver were seen in necrotic tissue and the lesion was diagnosed as a bleeding hepatocellular carcinoma (HCC). The non-cancerous liver tissue showed non-cirrhotic steatohepatitis. This was an unusual presentation of HCC.

Characteristic Features of Nonalcoholic Fatty Liver Disease in Japan with a Focus on the Roles of Age, Sex and Body Mass Index

This review provides an update on the characteristics of nonalcoholic fatty liver disease (NAFLD), with a focus on the effects of age, sex, and body mass index. Age is a risk factor for NAFLD progression; however, extremely old patients have unique features, namely, the associations between metabolic comorbidities and NAFLD are weaker and NAFLD is not a risk factor for mortality. The prevalence of NAFLD is higher in men than in premenopausal women, whereas the reverse is true after menopause. Thus, before menopause, estrogen may have protective effects against NAFLD. Our hospital data showed that over 25% of male patients with NAFLD and almost 40% of female patients with NAFLD, especially elderly patients, were nonobese. Although histological steatosis and activity were associated with body mass index, the prevalence of nonalcoholic steatohepatitis was not. The prevalence of advanced fibrosis showed a significant sex difference. Advanced fibrosis was significantly more frequent among severely obese men but the prevalence was lower among severely obese women. This difference could be because a substantial proportion of severely obese women were premenopausal; thus, estrogen may have much stronger effects on the development of fibrosis than on obesity. Further studies are required to develop tailored management strategies.

Steatohepatitis-Like Changes in Hepatocellular Adenoma

OBJECTIVES

Our aim was to investigate the frequency of steatohepatitic morphology in hepatocellular adenoma (HCA) and correlate with its clinical parameters and risk factors underlying nonalcoholic fatty liver disease (NAFLD) or nonalcoholic steatohepatitis (NASH).

METHODS

We examined a series of 41 liver resection specimens diagnosed with HCA for steatohepatitic changes. Background nonneoplastic liver was also evaluated. Clinical records were reviewed for risk factors of NAFLD/NASH.

RESULTS

Six steatohepatitic HCAs (SH-HCAs) were identified, with an overall prevalence of six (14.6%) of 41, of which three were HNF1α inactivated and three were inflammatory, but none were β-catenin mutated. Five of the six patients with SH-HCA had at least one known risk factor for NAFLD/NASH, including obesity (n = 4; 66.7%), diabetes (n = 5; 83.3%), hypertension (n = 3; 50%), and dyslipidemia (n = 1; 16.7%). Compared with the patients without SH-HCA, the patients with SH-HCA had a higher frequency of type 2 diabetes, obesity, and hypertension. Of the six SH-HCAs, background nonneoplastic liver showed significant steatosis in three (50%) cases and steatohepatitic changes in one (16.7%) case.

CONCLUSIONS

Approximately 15% of HCAs in our series demonstrated steatohepatitic changes. Lack of such morphology in β-catenin-mutated subtype suggests reassurance in this morphologic variant of HCA.

Hepatocellular carcinoma in young morbid obese patients with non-alcoholic fatty liver disease

We report the two youngest cases of hepatocellular carcinoma (HCC) in non-alcoholic fatty liver disease (NAFLD) among our 119 NAFLD-HCC patients. A 36-year-old man was referred to our hospital due to a 5 cm in diameter liver tumor with elevation of α-fetoprotein and des-γ-carboxy prothrombin found at his annual health check. He had no symptoms other than 20 kg weight loss. He has been morbidly obese since he was a child. At the time of the diagnosis of NAFLD-HCC, blood chemistry showed FIB4-index 0.52, α-fetoprotein 11.1 ng/mL and des-γ-carboxy prothrombin 361 mAU/mL. He underwent curative operation. The non-cancerous lesion showed steatohepatitis with mild fibrosis. A 41-year-old man was diagnosed as having a huge liver tumor (15 cm in diameter) during medical examination for 10 kg weight loss. He had no clinical symptoms except weight loss. He has been morbidly obese since childhood. NAFLD was diagnosed at age 20. At the time of the HCC diagnosis, blood chemistry showed FIB4-index 1.42, α-fetoprotein 1974 ng/mL, and des-γ-carboxy prothrombin 82,602 mAU/mL. He underwent curative operation. We have to be aware that HCC can develop in young NAFLD patients without advanced fibrosis. Concerning tumor markers, elevation of des-γ-carboxy prothrombin was more sensitive than α-fetoprotein.

The characteristics and risk factors of hepatocellular carcinoma in nonalcoholic fatty liver disease without cirrhosis

BACKGROUND AND AIM

We evaluated the characteristics of hepatocellular carcinoma (HCC) in patients who had non-alcoholic fatty liver disease (NAFLD) without cirrhosis.

METHODS

We prospectively followed NAFLD patients at our University hospital. NAFLD was diagnosed from detection of steatosis by histology or imaging, no alcohol intake, and exclusion of other liver diseases. Cirrhosis was defined by histological features, imaging data, and symptoms. We compared NAFLD-related HCC with or without cirrhosis and non-cirrhotic NAFLD with or without HCC.

RESULTS

There were 48 non-cirrhotic HCC patients and 71 cirrhotic HCC patients. Multiple logistic regression analysis revealed that other than liver function factors, male gender (OR: 5.603, 95%CI: 1.577-19.900), light drinker (OR: 2.797, 95%CI: 1.031-7.589), and tumor size (OR: 1.031, 95%CI 1.009-1.055) differ significantly between these two groups. The recurrence rate was significantly lower in the non-cirrhotic HCC group than the cirrhotic HCC group, with risk factors being des-γ-carboxy prothrombin and the number of HCCs. The non-cirrhotic HCC group showed significantly better survival because of absence of non-cancerous liver failure. Comparison between non-cirrhotic NAFLD patients with or without HCC (n = 612) revealed the following risk factors for HCC: male gender (OR: 7.774, 95%CI: 2.176-27.775), light drinker (OR: 4.893, 95%CI: 1.923-12.449), and high FIB4 index (OR 2.634, 95%CI: 1.787-3.884).

CONCLUSION

In patients with non-cirrhotic NAFLD, important risk factors for HCC were male gender, alcohol consumption, and the FIB4 index. HCC recurrence and survival were only influenced by the tumor stage. We should be aware of alcohol consumption as a modifiable risk factor for HCC.

Factors influencing subclinical atherosclerosis in patients with biopsy-proven nonalcoholic fatty liver disease

Although the presence of nonalcoholic fatty liver disease (NAFLD) is known to be related to subclinical atherosclerosis, the relationship between the severity of NAFLD and subclinical atherosclerosis is not clear. This study aimed to clarify the factors related to subclinical arteriosclerosis, including the histopathological severity of the disease and PNPLA3 gene polymorphisms, in NAFLD patients. We measured brachial-ankle pulse wave velocity (baPWV) as an index of arterial stiffness in 153 biopsy-proven NAFLD patients. The baPWV values were significantly higher in the advanced fibrosis group than in the less advanced group (median, 1679 cm/s vs 1489 cm/s; p = 5.49×10⁻⁴). Multiple logistic regression analysis revealed that older age (≥55 years) (p = 8.57×10⁻³; OR = 3.03), hypertension (p = 1.05×10⁻³; OR = 3.46), and advanced fibrosis (p = 9.22×10⁻³; OR = 2.94) were independently linked to baPWV ≥1600 cm/s. NAFLD patients were categorized into low-risk group (number of risk factors = 0), intermediate-risk group (= 1), and high-risk group (≥2) based on their risk factors, including older age, hypertension, and biopsy-confirmed advanced fibrosis. The prevalence of baPWV ≥1600 cm/s was 7.1% (3/42) in the low-risk group, 30.8% (12/39) in the intermediate-risk group, and 63.9% (46/72) in the high-risk group. Non-invasive liver fibrosis markers and scores, including the FIB-4 index, NAFLD fibrosis score, hyaluronic acid, Wisteria floribunda agglutinin positive Mac-2-binding protein, and type IV collagen 7s, were feasible substitutes for invasive liver biopsy. Older age, hypertension, and advanced fibrosis are independently related to arterial stiffness, and a combination of these three factors may predict risk of arteriosclerosis in NAFLD patients.

Update on hepatocellular carcinoma: Pathologists’ review

Histopathologic diversity and several distinct histologic subtypes of hepatocellular carcinoma (HCC) are well-recognized. Recent advances in molecular pathology and growing knowledge about the biology associated with distinct histologic features and immuno-profile in HCC allowed pathologists to update classifications. Improving sub-classification will allow for more clinically relevant diagnoses and may allow for stratification into biologically meaningful subgroups. Therefore, immuno-histochemical and molecular testing are not only diagnostically useful, but also are being incorporated as crucial components in predicting prognosis of the patients with HCC. Possibilities of targeted therapy are being explored in HCC, and it will be important for pathologists to provide any data that may be valuable from a theranostic perspective. Herein, we review and provide updates regarding the pathologic sub-classification of HCC. Pathologic diagnostic approach and the role of biomarkers as prognosticators are reviewed. Further, the histopathology of four particular subtypes of HCC: Steatohepatitic, clear cell, fibrolamellar and scirrhous - and their clinical relevance, and the recent consensus on combined HCC-cholangiocarcinoma is summarized. Finally, emerging novel biomarkers and new approaches to HCC stratification are reviewed.