Hepatocellular carcinoma arising from hepatocellular adenoma in a hepatitis B virus-associated cirrhotic liver. Clin Radiol. 2012;67:329-333. [PMID: 22079485 DOI: 10.1016/j.crad.2011.09.003]

Pediatric Hepatocellular Adenomas: What Is Known and What Is New?

Current understanding and classification of pediatric hepatocellular adenomas (HCA) are largely based on adult data. HCAs are rare in children and, unlike in adults, are often seen in the context of syndromes or abnormal background liver. Attempts to apply the adult classification to pediatric tumors have led to several "unclassifiable" lesions. Although typically considered benign, few can show atypical features and those with beta-catenin mutations have a risk for malignant transformation. Small lesions can be monitored while larger (>5.0 cm) lesions are excised due to symptoms or risk of bleeding/rupture, etc. Management depends on gender, age, underlying liver disease, multifocality, size of lesion, histologic subtype and presence of mutation, if any. In this review, we summarize the data on pediatric HCAs and highlight our experience with their diagnosis and management.

Focal Liver Lesions other than Hepatocellular Carcinoma in Cirrhosis: Diagnostic Challenges

Liver cirrhosis is associated with regenerative nodules and an increased risk of developing hepatocellular carcinoma (HCC). However, other benign and malignant liver lesions may also occur. Differentiating the other lesions from HCC is important for further therapeutic decisions. This review discusses the characteristics of non-HCC liver lesions in cirrhosis and their consequent appearance on contrast-enhanced ultrasonography (CEUS) with consideration of other imaging. Knowledge of this data would be helpful in avoiding misdiagnoses.

Prevalence of benign focal liver lesions and non-hepatocellular carcinoma malignant lesions in liver cirrhosis

Liver cirrhosis is associated with an increased risk of developing hepatocellular carcinoma (HCC). However, other benign and malignant liver lesions may co-exist or may be the only focal liver lesion (FLL) detected. Compared to HCC, comparatively little is known about the frequency and natural history of benign FLL in patients with established liver cirrhosis.

This review analyses the prevalence and frequency of benign and malignant FLL others than hepatocellular carcinoma (HCC) in liver cirrhosis including imaging and autopsy studies. Understanding these data should be helpful in avoiding misdiagnoses.

Focal liver lesions in cirrhosis: Role of contrast-enhanced ultrasonography

Contrast-enhanced ultrasound (CEUS) represents a great innovation for the evaluation of focal liver lesions (FLLs). The main advantage of CEUS is the real-time imaging examination and the very low toxicity in patients with renal failure. Liver cirrhosis has been recognized as a major risk factor for the onset of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). HCC in liver cirrhosis develops as the last step of a complex that leads to the gradual transformation from regenerative nodule through dysplastic nodule to HCC. In patients with liver cirrhosis, a surveillance program is recommended consisting of ultrasound (US) for detecting small focal lesions. A wide spectrum of benign and malignant lesions other than HCC may be found in the cirrhotic liver and their differentiation is important to avoid errors in staging diseases that may preclude potentially curative therapies. Several published studies have explored the value of CEUS in liver cirrhosis and they have been shown to have excellent diagnostic and prognostic performances for the evaluation of non-invasive and efficient diagnosis of FLLs in patients at high risk for liver malignancies. The purpose of this article is to describe and discuss CEUS imaging findings of FLLs including HCC and ICC, all of which occur in cirrhotic livers with varying prevalence.

Hepatocellular adenoma in the paediatric population: Molecular classification and clinical associations

Hepatocellular adenomas (HCAs) represent rare, benign liver tumours occurring predominantly in females taking oral contraceptives. In children, HCAs comprise less than 5% of hepatic tumours and demonstrate association with various conditions. The contemporary classification of HCAs, based on their distinctive genotypes and clinical phenotypes, includes hepatocyte nuclear factor 1 homeobox alpha-inactivated HCAs, beta-catenin-mutated HCAs, inflammatory HCAs, combined beta-catenin-mutated and inflammatory HCAs, sonic hedgehog-activated HCAs, and unclassified HCAs. In children, there is a lack of literature on the characteristics and distribution of HCA subtypes. In this review, we summarized different HCA subtypes and the clinicopathologic spectrum of HCAs in the paediatric population.

MR imaging of hepatocellular adenomas on genotype-phenotype classification: A report from China

PURPOSE

To investigate and compare the MR features between hepatocellular adenoma (HCA) subtypes in China, including preliminary observations on diffusion-weighted imaging (DWI).

METHODS

Thirty-six patients with 39 pathologically proven HCAs underwent gadopentetate dimeglumine enhanced MRI. The morphological and imaging features on T1, T2-weighted, dynamic-enhanced imaging and DWI were retrospectively evaluated and compared between four HCA subtypes, using Kruskal-Wallis test, Fisher's exact test and Dunn-Bonferroni post hoc test.

RESULTS

HCA frequently occurred in male (n = 19, 52.8%), lacked an association with oral contraceptives (n = 0), and had a relatively high incidence of coexistent Hepatitis B infection (n = 6, 16.7%). Signals on T1 and T2-weighted imaging, enhancement pattern and intensity, lesion heterogeneity, as well as accompanying findings including lesion steatosis, necrosis or cystic component, central scar, and pseudocapsule were different between HCA subtypes (P < .0001 to P = .019). Apparent diffusion coefficient (ADC) values among HCA subtypes were different as a whole (P = .029), within which β-catenin-mutated HCA had the lowest ADCs; but post hoc comparisons demonstrated no significant differences between groups (P = .066-1.000).

CONCLUSION

Both clinical and MR imaging presentation of HCA in China had some specific characteristics, and a good relationship existed between MR data and genotype-phenotype classification. Furthermore, ADC value may provide a potential indicator of malignant transformation.

乙型肝炎合并肝脏巨大腺瘤1例

肝细胞腺瘤(hepatocellular adenoma, HCA)是一种较为罕见的肝内良性肿瘤, 生长缓慢, 发现时体积常较大并伴出血坏死. HCA多见于年轻女性, 常与口服避孕药有关, 本文就乙型肝炎合并肝脏巨大腺瘤1例进行论述.

Focal lesions in cirrhotic liver: what else beyond hepatocellular carcinoma?

Detection and characterization of focal lesions in the cirrhotic liver may pose a diagnostic dilemma. Several benign and malignant lesions may be found in a cirrhotic liver along with hepatocellular carcinoma (HCC), and may exhibit typical or atypical imaging features. In this pictorial essay, we illustrate computed tomography and magnetic resonance imaging findings of lesions such as simple bile duct cysts, hemangioma, focal nodular hyperplasia-like nodules, peribiliary cysts, intrahepatic cholangiocarcinoma, lymphoma, and metastases, all of which occur in cirrhotic livers with varying prevalences. Pseudolesions, such as perfusion anomalies, focal confluent fibrosis, and segmental hyperplasia, will also be discussed. Imaging characterization of non-HCC lesions in cirrhosis is important in formulating an accurate diagnosis and triaging the patient towards the most appropriate management.

Hepatocellular adenoma with malignant transformation in male patients with non-cirrhotic livers

Introduction

Hepatocellular adenomas (HCAs), with a risk of malignant transformation into hepatocellular carcinoma (HCC), classically develop in young women who are taking oral contraceptives. It is now clear that HCAs may also occur in men. However, it is rarely reported that HCAs with malignant transformation occur in male patients with non-cirrhotic livers. This study aimed to characterize the malignancy of HCAs occurring in male patients.

Methods

All patients with HCAs with malignant transformation who underwent hepatectomy at the Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College between January 1, 1999 and December 31, 2011 were enrolled in the study. The clinical characteristics as well as radiologic and pathologic data were reviewed.

Results

HCAs with malignant transformation were observed in 5 male patients with non-cirrhotic livers, but not in female patients. The alpha-fetoprotein (AFP) levels were higher in patients with HCAs with malignant transformation than in patients with HCAs without malignant transformation. The diameters of the tumors with malignant transformation were larger than 5 cm in 3 cases and smaller than 5 cm in 2 cases. The 5 patients were all alive without recurrence by the end of the study period. The disease-free survival times of the 5 patients were 26, 48, 69, 69, and 92 months.

Conclusion

Our results indicate that resection would be advised even if the presumptive diagnosis is adenoma smaller than 5 cm in diameter, especially in male patients.

Hepatocellular carcinoma arising in adenoma: similar immunohistochemical and cytogenetic features in adenoma and hepatocellular carcinoma portions of the tumor

Well-differentiated hepatocellular carcinoma in non-cirrhotic liver can show morphological features similar to hepatocellular adenoma. In rare instances, hepatocellular carcinoma can arise in the setting of hepatocellular adenoma. This study compares the immunohistochemical and cytogenetic features of the hepatocellular adenoma-like and hepatocellular carcinoma portions of these tumors. Immunohistochemistry for β-catenin, glutamine synthetase, serum amyloid A protein, glypican-3, and heat-shock protein 70 was done in 11 cases of hepatocellular carcinoma arising in hepatocellular adenoma in non-cirrhotic liver. Tumors with nuclear β-catenin and/or diffuse glutamine synthetase were considered β-catenin activated. Fluorescence in situ hybridization (FISH) was done in nine cases for gains of chromosomes 1, 8 and MYC. There were seven men (33-75 years) and four women (29-65 years). Focal atypical morphological features were seen in hepatocellular adenoma-like areas in 7 (64%) cases. Hepatocellular adenoma-like areas showed features of inflammatory hepatocellular adenoma in 7 (64%) cases; 4 of these were also serum amyloid A-positive in the hepatocellular carcinoma portion. β-Catenin activation, heat-shock protein 70 positivity, and chromosomal gains on FISH were seen in the hepatocellular adenoma portion in 55%, 40%, and 56% of cases, and 73%, 60%, and 78% of cases in the hepatocellular carcinoma portion, respectively. In conclusion, the hepatocellular adenoma-like portion of most cases of hepatocellular carcinoma arising in hepatocellular adenoma shows features typically seen in hepatocellular carcinoma such as focal morphological abnormalities, β-catenin activation, heat-shock protein 70 expression, and chromosomal gains. Hepatocellular adenoma-like areas in these tumors, especially in men and older women, may represent an extremely well-differentiated variant of hepatocellular carcinoma, whereas the morphologically recognizable hepatocellular carcinoma portion represents a relatively higher grade component of the tumor.

Update on the new classification of hepatic adenomas: clinical, molecular, and pathologic characteristics

CONTEXT

Hepatic adenoma is an uncommon, benign, hepatic neoplasm that typically occurs in women of child-bearing age, often with a history of long-term use of oral contraceptive drugs. This is usually detected as an incidental mass lesion in a noncirrhotic liver during imaging studies. Pathologic evaluation by needle core biopsy remains the gold standard for diagnosis. Molecular studies have revealed that hepatic adenomas involve unique molecular pathways that are distinct from hepatocellular carcinoma. Based on these studies, a French collaborative group has recently proposed a molecular-pathologic classification for hepatic adenomas. In addition, advances in molecular studies have led to reclassification of the "telangiectatic variant of focal nodular hyperplasia" as "hepatic adenoma, inflammatory subtype."

OBJECTIVE

To review the proposed, new classification of hepatic adenoma and the changes in diagnostic workup in light of the above-mentioned developments.

DATA SOURCES

Review of published literature and illustrations from clinical case material.

CONCLUSIONS

Definitive diagnosis of liver mass lesion on needle core biopsies has a decisive role in clinical management. With the advent of the new classification of hepatic adenomas and its prognostic implications, it is vital for pathologists to be aware of the morphologic features seen in different subtypes and the available diagnostic tools, such as immunohistochemistry, to help identify the correct subtype.

Focal Nodular Hyperplasia and Hepatocellular Adenoma around the World Viewed through the Scope of the Immunopathological Classification

Focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) are benign hepatocellular tumors. The risk of bleeding and malignant transformation of HCA are strong arguments to differentiate HCA from FNH. Despite great progress that has been made in the differential radiological diagnosis of the 2 types of nodules, liver biopsy is sometimes necessary to separate the 2 entities. Identification of HCA subtypes using immunohistochemical techniques, namely, HNF1A-inactivated HCA (35-40%), inflammatory HCA (IHCA), and beta-catenin-mutated inflammatory HCA (b-IHCA) (50-55%), beta-catenin-activated HCA (5-10%), and unclassified HCA (10%) has greatly improved the diagnostic accuracy of benign hepatocellular nodules. If HCA malignant transformation occurs in all HCA subgroups, the risk is by far the highest in the β -catenin-mutated subgroups (b-HCA, b-IHCA). In the coming decade the management of HCA will be more dependent on the identification of HCA subtypes, particularly for smaller nodules (<5 cm) in terms of imaging, follow-up, and resection.