A case of progressing focal nodular hyperplasia and its molecular expression pattern

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

Management of focal nodular hyperplasia of the liver: Experience of 50 pediatric patients in a tertiary center

BACKGROUND

Focal nodular hyperplasia (FNH) is a rare benign hepatic lesion in children. No management guidelines for pediatric population exist because of limited evidence.

OBJECTIVE

To review the experience of a large tertiary liver center, providing additional clinical data to help formulate management guidelines for FNH in the pediatric population.

METHODS

We analyzed data of children <18 years diagnosed with FNH from 1996 to 2018 at our hospital, detailing management and long-term clinical outcome.

RESULTS

50 patients were identified. The median age was 10 years old (range 0.75-15.5 years old). The mean diameter of FNH was 5.9 cm (±3.1 cm). 10 patients had multiple lesions. First-line management: watchful waiting with serial checks (n = 37), surgery (n = 13). Of the watchful waiting patients, 10 required eventual second-line surgery. After a median follow-up of 4.7 years (range 0.5-20 years), 46 patients were asymptomatic, with no significant difference in clinical outcome (p = 0.962) between the two first-line management approaches. Lesions demonstrated growth in 13 cases: 5 of these required second-line surgery. In these patients, there was no significant difference in clinical outcome (p = 0.188) compared to nonoperative patients. Considering all surgically treated patients, there was no significant difference between first-line and second-line surgery for clinical outcome (p = 0.846), hospital stay (p = 0.410), complications (p = 0.510) and severe complications (p = 0.385).

CONCLUSIONS

Our data support the hypothesis that watchful waiting is a safe initial approach to pediatric FNH management in patients with no major symptoms or complications. Surgery should be reserved for patients with diagnostic doubt, persistent symptoms and/or biological or significant anatomical abnormalities. FNH growth alone should not be considered as an indication for surgery.

TYPE OF STUDY

Therapeutic study.

LEVEL OF EVIDENCE

Level III.

The potentiality of laparoscopic partial liver excisional biopsy using analysis of the liver surface based on preoperative 3D simulation imaging: A case report

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Ultrasonography or CT guided biopsy is useful for diagnosis of liver tumors.

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Some tumors were not detectable with any modality except only MRI.

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3D simulation liver imaging can be created with CT and MRI images.

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Excisional biopsy using preoperative 3D simulation could provide a certain biopsy.

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Present biopsy method is effective for tumors that cannot be detected by CT or US.

Introduction

The imaging diagnostics of liver tumor are difficult. There are no effective biopsy examinations for liver tumors that cannot be detected even by ultrasonography (US) and computed tomography (CT). We report a remarkably useful biopsy method for such tumors.

Presentation of case

A 67-year-old man with hepatitis C underwent gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging, and the images revealed multiple delayed enhanced masses that showed high signal intensity in the hepatobiliary phase. The possibility of malignancy could not be ruled out due to the trend towards increased size of the masses. Percutaneous liver biopsy was considered impossible because CT and US could not detect the masses. Laparoscopic liver biopsy with preoperative simulation using 3D imaging was performed. The 3D imaging provided accurate information of liver surface irregularities with cirrhosis change. The tumor location was confirmed, and adequate tumor excisional biopsy was performed. Histological assessment revealed the tumor to be a focal nodular hyperplasia-like nodule.

Discussion and conclusions

Laparoscopic liver biopsy has been widely used because of its safety and accuracy. It enables accurate resection of tumors that are undetectable with CT and US by employing preoperative 3D imaging while maintaining the less-invasiveness.

Evolution and revolution of laparoscopic liver resection in Japan

Due to important technological developments and improved endoscopic techniques, laparoscopic liver resection (LLR) is now considered the approach of choice and is increasingly performed worldwide. Recent systematic reviews and meta‐analyses of observational data reported that LLR was associated with less bleeding, fewer complications, and no oncological disadvantage; however, no prospective randomized trials have been conducted. LLR will continue to evolve as a surgical approach that improves patient's quality of life. LLR will not totally supplant open liver surgery, and major LLR remains to be technically challenging procedure. The success of LLR depends on individual learning curves and adherence to surgical indications. A recent study proposed a scoring system for stepwise application of LLR, which was based on experience at high‐volume Japanese centers. A cluster of deaths after major LLR was sensationally reported by the Japanese media in 2014. In response, the Japanese Society of Hepato‐Biliary‐Pancreatic Surgery conducted emergency data collection on operative mortality. The results demonstrated that mortality was not higher than that for open procedures except for hemi‐hepatectomy with biliary reconstruction. An online prospective registry system for LLR was established in 2015 to be transparent for patients who might potentially undergo treatment with this newly developed, technically demanding surgical procedure.