A case of hepatocellular carcinoma arising within large focal nodular hyperplasia with review of the literature

Multi-omics characterization reveals the pathogenesis of liver focal nodular hyperplasia

The molecular landscape and pathogenesis of focal nodular hyperplasia (FNH) have yet to be elucidated. We performed multi-omics approaches on FNH and paired normal liver tissues from 22 patients, followed by multi-level bioinformatic analyses and experimental validations. Generally, FNH had low mutation burden with low variant allele frequencies, and the mutation frequency significantly correlated with proliferation rate. Although no recurrently deleterious genomic events were found, some putative tumor suppressors or oncogenes were involved. Mutational signatures indicated potential impaired mismatch function and possible poison contact. Integrated analyses unveiled a group of FNH specific endothelial cells that uniquely expressed SOST and probably had strong interaction with fibroblasts through PDGFB/PDGFRB pathway to promote fibrosis. Notably, in one atypical FNH (patient No.11) with pronounced copy number variations, we observed a unique immune module. Most FNH are benign, but molecularly atypical FNH still exist; endothelial cell derived PDGFB probably promotes the fibrogenic process in FNH.

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FNHs are genetically stable, but high mutation cases exist

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FNHs have unique transcriptomic modules, and they alter in atypical FNH

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FNH has a unique type of SOST-expressing endothelial cells that may promote fibrosis

Huge focal nodular hyperplasia presenting in a 6-year-old child: A case presentation

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FNH is a benign lesion of the liver which is rare in children.

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We report the case of a 6-year-old child (male) with a huge FNH which size is more than 10 cm. This could be the biggest FNH among all children’s FNH cases ever reported.

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When pediatric FNH patients accord with (1) clinical symptoms; (2) indefinite diagnosis or hepatitis B virus carriage; (3) tumor size >5 cm, surgical treatment could be considered.

Introduction

Focal nodular hyperplasia (FNH) is a benign lesion of the liver which is usually found in healthy adults, however, FNH is rare in children, and comprises only 2% of all pediatric liver tumors. Herein, we report the case of a 6-year-old child (male) with a huge FNH which size is more than 10 cm. This could be the biggest FNH among all children’s FNH cases ever reported.

Case presentation

A 6-year-old boy was found a hepatic space-occupying lesion two years ago. As the time went by, the lesion became bigger gradually. The last CT examination showed the size of the tumor to be 10.5 × 9.9 cm in the right hepatic lobe. This child underwent surgical resection of the tumor which was confirmed as FNH (11 × 8 × 7 cm) by pathology.

Conclusion

FNH is a benign lesion of the liver, and it is characterized by hepatocyte hyperplasia and a central stellate scar. It is uncommon for FNH to be diagnosed in children. Such huge FNH (about 11 cm) is extremely rare. Surgical operation may be the effective method to cure huge FNH.

Huge focal nodular hyperplasia difficult to distinguish from well-differentiated hepatocellular carcinoma

We present a 43-year-old man with huge focal nodular hyperplasia (FNH) that was difficult to distinguish from well-differentiated hepatocellular carcinoma (HCC). He previously had abnormal portal vein circulation due to hypoplasia of the intrahepatic portal vein, which was treated with a superior mesenteric vein-inferior vena cava shunt. Laboratory findings included predominantly indirect hyperbilirubinemia with concomitant elevation in aspartate aminotransferase (AST), alanine aminotransferase (ALT), and ammonia. Serum α-fetoprotein and des-γ-carboxy prothrombin were slightly elevated. Multidetector-row computed tomography detected the primary tumor in the left liver lobe, which partially showed a central stellate scar. Gd ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging showed some low-intensity areas in the tumor in the hepatocyte phase. 99mTc-galactosyl human serum albumin scintigraphy showed normal intake of agent in the tumor. We could not rule out well-differentiated HCC. Extended left hepatectomy was performed. Final histopathological findings showed that most of the tumor was FNH against a background of portal vein hypoplasia with moderate atypia and hemorrhage. And immunohistochemical analysis revealed high expression of organic anion transporter (OATP) 1B3 and low expression of multidrug resistance-associated protein (MRP) 2 in a part of the tumor. The patient has remained alive with no hepatic lesion for 1 year after surgery. We describe a case of huge FNH that was difficult to distinguish from well-differentiated HCC even by current fully preoperative imaging technology and demonstrate the effectiveness of curative surgical resection.

Focal nodular hyperplasia--a review of myths and truths

BACKGROUND

Focal nodular hyperplasia (FNH) is a benign hyperplastic lesion of the liver with no known malignant potential. It has generated much interest due to the frequency with which it presents with atypical features on radiological imaging. Often resulting in misdiagnosis. Moreover, the understanding of particular subtypes of this lesion at a molecular level has changed in recent years. This may have implications on how certain subtypes should be managed.

PURPOSE

This review aims to analyse current literature pertaining to FNH and to provide clinically relevant advice regarding diagnosis and management.

Focal nodular hyperplasia or focal nodular hyperplasia-like lesions of the liver: a special emphasis on diagnosis

BACKGROUND AND AIM

Focal nodular hyperplasia (FNH) and FNH-like lesions are hypervascular masses that can mimic hepatocellular carcinoma (HCC). We have investigated the clinical, radiological and pathological features of FNH and FNH-like lesions of the liver, with particular focus on the aspect of diagnosis.

METHODS

A total of 84 patients, 77 with pathologically-proven FNH and seven with FNH-like lesions of the liver, were analyzed retrospectively.

RESULTS

Of the 84 patients, seven had underlying liver cirrhosis, including two with Budd-Chiari syndrome and one with cardiac cirrhosis. These cases were therefore classified as having FNH-like lesions. Two of the remaining 77 patients without underlying liver cirrhosis were positive for hepatitis B surface antigen. Seven of 50 (14.0%) patients evaluated by four-phase computed tomography (CT) showed portal or delayed washout, and three of 28 (10.7%) patients analyzed by three-phase CT showed washout on the portal phase. Collectively, three of nine (33.3%) patients with risk factors for HCC could have been wrongly diagnosed with HCC based on the non-invasive diagnostic criteria for HCC. A central scar was observed in 30 patients (35.7%) radiologically. Among 62 patients who underwent percutaneous needle biopsy, four patients (6.5%) were misdiagnosed as having HCC and two patients (3.2%) had inconclusive results by a first needle biopsy.

CONCLUSIONS

The presence of a hepatic lesion with arterial hypervascularity and/or portal/delayed washout is not necessarily diagnostic of HCC, particularly in patients without risk factors for HCC. These radiological findings can also occur in cirrhotic patients with FNH-like lesions, including those with hepatic outflow obstruction.

Adenoma or atypical hepatic focal nodular hyperplasia: role of preoperative imaging and laparoscopic treatment

Differentiation of focal nodular hyperplasia (FNH) and other hypervascular liver lesions, such as hepatocellular adenoma (HCA), is important because of the drastically different therapeutic approach. However, FNH can be well distinguished only if it shows a typical aspect; alternatively, in the case of atypical FNH, imaging findings are not specific enough to provide a secure diagnosis and histologic verification of the lesion is required. In addition, HCA cannot be identified conclusively by any current available imaging technique and it can be at best suspected strongly, and this suspicion may lead to liver resection. Herein we report a case of a patient with an unusual FNH nodule presenting at ultrasonographic scanning as an isoechoic mass arising from hepatic segment 4b; the diagnostic indecision between FNH and HCA was not definitively solved even after computed tomography scan and magnetic resonance imaging and the patient was scheduled for a laparoscopic resection. The pathologic examination diagnosed an atypical FNH nodule. The clinical doubt between FNH and HCA remains a problem affecting the clinicians, and more effort should be made in the direction of a better preoperative differentiation of such different conditions. Surgical resection should not be considered as the failure of the preoperative diagnostic attempt, but as the mainstay for a definitive and sure diagnosis.

Focal nodular hyperplasia of the liver in a 5-year-old girl

Focal nodular hyperplasia of the liver is a benign tumor that usually affects young women. Traditionally, its treatment in children has been conservative. As a result of its rarity in childhood, its differential diagnosis with other liver tumors is challenging. We present the case of a 5-year-old girl with a 1-week history of fever and abdominal pain. No definite diagnosis could be obtained after serial imaging and liver biopsy. As a result of uncertainty in the imaging and needle biopsy results, the patient underwent complete tumor resection. Pathology showed focal nodular hyperplasia that affected the right lobe of the liver. After surgery, the child was doing well at 24 months of follow-up.

Research on focal nodular hyperplasia with MSCT and postprocessing

AIM: To investigate and evaluate the pathological features and diagnostic value of focal nodular hyperplasia (FNH) with multi-section spiral computed tomography (MSCT) and postprocessing.

METHODS: A total of 25 patients with FNH who had undergone MSCT and postprocessing were included in the investigation. All patients had been pathologically or clinically confirmed with FNH. A number of 75 cases of hepatic carcinomas, hemangiomas and adenomas were randomly selected at a same period for a comparative study.

RESULTS: There was a single focus in 22 cases and multiple foci in 3 cases. On the plain scan, 17 lesions showed hypodensity, 7 isodensity and 4 hyperdensity (the case with fatty liver). With contrast, 28 lesions were enhanced evenly or in the nodules in the arterial phase; 13 lesions still showed hyperdensity, 11 lesions isodensity and 4 lesions hypodensity in the parenchymatous phase; in the delayed phase only 5 lesions showed hyperdensity but 9 lesions showed isodensity or slight hypodensity and 14 lesions showed hypodensity. Twelve lesions of 28 had central asteroid scars. Thickened feeding arteries in postprocessing were seen in 24 lesions, and were integrated into the parenchymatous lesions with a gradual and smooth course. On the contrary, there were no artery penetrated into the lesion found in any of comparative hepatic tumors.

CONCLUSION: Doctors could make a correct diagnosis and differentiation of FNH on evaluation of the characteristic appearance on MSCT with postprocessing.

Clonality and allelotype analyses of focal nodular hyperplasia compared with hepatocellular adenoma and carcinoma

AIM: To identify clonality and genetic alterations in focal nodular hyperplasia (FNH) and the nodules derived from it.

METHODS: Twelve FNH lesions were examined. Twelve hepatocellular adenomas (HCAs) and 22 hepatocellular carcinomas (HCCs) were used as references. Nodules of different types were identified and isolated from FNH by microdissection. An X-chromosome inactivation assay was employed to describe their clonality status. Loss of heterozygosity (LOH) was detected, using 57 markers, for genetic alterations.

RESULTS: Nodules of altered hepatocytes (NAH), the putative precursors of HCA and HCC, were found in all the FNH lesions. Polyclonality was revealed in 10 FNH lesions from female patients, and LOH was not detected in any of the six FNH lesions examined, the results apparently showing their polyclonal nature. In contrast, monoclonality was demonstrated in all the eight HCAs and in four of the HCCs from females, and allelic imbalances were found in the HCAs (9/9) and HCCs (15/18), with chromosomal arms 11p, 13q and 17p affected in the former, and 6q, 8p, 11p, 16q and 17p affected in the latter lesions in high frequencies (≥ 30%). Monoclonality was revealed in 21 (40%) of the 52 microdissected NAH, but was not found in any of the five ordinary nodules. LOH was found in all of the 13 NAH tested, being highly frequent at six loci on 8p, 11p, 13q and 17p.

CONCLUSION: FNH, as a whole, is polyclonal, but some of the NAH lesions derived from it are already neoplastic and harbor similar allelic imbalances as HCAs.

Natural course of hepatic focal nodular hyperplasia: a long-term follow-up study with sonography

PURPOSE

We aimed to investigate the natural course of hepatic focal nodular hyperplasia (FNH) in a long-term follow-up study with sonography.

METHOD

This study comprised 30 patients (24 women and 6 men) with 34 FNHs. Diagnosis of FNH was made using color Doppler sonography, contrast-enhanced CT, or MRI in combination with needle biopsy. Patients were followed every 3 to 6 months with sonography. Regression or progression of tumor was defined as a change of over 30% in maximal diameter. Disappearance was defined as no vizualization of the tumor on at least 3 follow-up sonographic examinations.

RESULTS

Thirty-four FNHs were followed over a mean period of 42 months (range, 7-95 months). Twenty-four lesions (70.6%) were stable in size, 1 (2.9%) progressed, and 9 (26.5%) regressed. Of those that regressed, 6 (17.6%) disappeared over a mean period of 59 +/- 30 months (range, 20-95 months). Older age (OR 1.26, 95% CI 1.02-1.56; p < 0.05) and longer follow-up time (OR 1.11, 95% CI 1.01-1.21; p < 0.05) were the independent factors associated with complete regression of FNH.

CONCLUSION

Most FNHs were stable or regressed/disappeared after a long follow-up period. Based on the benign course, conservative treatment for asymptomatic FNH should be advocated.