Hepatocellular Carcinoma, Fibrolamellar Variant: Diagnostic Pathologic Criteria and Molecular Pathology Update. A Primer

Pedunculated Focal Nodular Hyperplasia: When in Doubt, Should We Cut It Out?

Focal nodular hyperplasia (FNH) is the second most common benign hepatic tumor and can rarely present as an exophytic solitary mass attached to the liver by a stalk. Most FNH cases are usually detected as incidental findings during surgery, imaging or physical examination and have a high female predominance. However, the pedunculated forms of FNH are particularly rare and commonly associated with severe complications and diagnostic challenges. Hence, our study aims to provide a comprehensive summary of the available data on the pedunculated FNH cases among adults and children. Furthermore, we will highlight the role of different therapeutic options in treating this clinical entity. The use of imaging techniques is considered a significant addition to the diagnostic toolbox. Regarding the optimal treatment strategy, the main indications for surgery were the presence of symptoms, diagnostic uncertainty and increased risk of complications, based on the current literature. Herein, we also propose a management algorithm for patients with suspected FNH lesions. Therefore, a high index of suspicion and awareness of this pathology and its life-threatening complications, as an uncommon etiology of acute abdomen, is of utmost importance in order to achieve better clinical outcomes.

Mitochondrial Dysfunction and Induction of Apoptosis in Hepatocellular Carcinoma and Cholangiocarcinoma Cell Lines by Thymoquinone

Thymoquinone (TQ), a plant-based bioactive constituent derived from the volatile oil of Nigella sativa, has been shown to possess some anti-neoplastic activities. The present study aimed to investigate the mitochondria and apoptosis observed when TQ is applied against hepatocellular carcinoma (HepG2) and cholangiocarcinoma (HuCCT1) cells, two of the most common primary tumors of the liver. All cell lines were treated with increasing concentrations of TQ for varying durations. The anti-proliferative effect of TQ was measured using the methoxyphenyl-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and resulted in dose- and time-dependent growth inhibition in both cell lines. Cell cycle, apoptosis, and assessment of mitochondria viability by morphology assessment and evaluation of the mitochondrial membrane potential were investigated. The present study confirms that TQ caused cell cycle arrest at different phases and induced apoptosis in both cell lines. A systematic review of rodent animal models was also carried out. Overall, our data seem to represent the most robust results, suggesting that TQ possesses promising therapeutic potential as an anti-tumor agent for the treatment of hepatocellular carcinoma and cholangiocarcinoma.

Juvenile Hepatocellular Carcinoma in a Healthy Liver

Primary hepatocellular carcinoma (HCC) in patients <30 years old is extremely rare. In younger patients, HCC develops against a background of persistent hepatitis B virus infection. We herein report a 23-year-old woman with HCC with all-negative hepatitis virus markers developing in an apparently healthy liver. Imaging studies showed a 50-mm hypervascular mass in segment 4 of the left liver lobe, compatible with HCC. The patient underwent surgical resection. A histological examination showed the presence of poorly differentiated HCC. The patient was diagnosed with HCC developing in a healthy liver. This is an extremely rare case of non-B non-C HCC.

‘Teratoid’ Hepatoblastoma: An Intriguing Variant of Mixed Epithelial-Mesenchymal Hepatoblastoma

Liver neoplasms are quite rare in childhood. They often involve 6.7 cases per 10 million children aged 18 years or younger. Hepatoblastoma (HB) is the most frequent tumor, but this neoplasm’s rarity points essentially to the difficulty of performing biologic studies and large-scale therapeutic trials. On the pathological ground, HB is separated into an entirely epithelial neoplasm or a mixed neoplasm with epithelial and mesenchymal components. This last category has been further subdivided into harboring teratoid features or not. The ‘teratoid’ HB includes a mixture of components with heterologous origin. The heterologous components include neuroectoderm, endoderm, or melanin-holding cells with or without mesenchymal components. The most important criterium for the teratoid component is neuroepithelium, melanin, and, more recently, a yolk-sac-like component and neuroendocrine components. The mesenchymal components include muscle, osteoid, and cartilage, which are most often observed mainly in ‘teratoid’ neoplasms. The teratoid component or mesenchymal components are diagnosed with biopsies. They appear more prominent after chemotherapy due to the response and shrinkage of epithelial elements and non- or low-responsive components of mixed HB. This review focuses on the clinical, radiological, and pathological findings of HB with teratoid features.

Pediatric fibrolamellar hepatocellular carcinoma: case report and review of the literature

BACKGROUND

A 13-year-old boy presented with acute abdominal pain in the right upper quadrant without previous trauma. Abdominal ultrasound (US) revealed a mass in the right liver lobe with free intraperitoneal fluid, suggestive for hemoperitoneum. Magnetic resonance imaging confirmed a subcapsular lesion (5.7 × 4.6 × 4.1 cm), suggestive for fibrolamellar hepatocellular carcinoma (FL-HCC). Positron emission tomography-computed tomography revealed mild to moderate fluorodeoxyglucose (FDG) avidity, with no other FDG avid lesions. Hepatic tumor markers were negative.

CASE REPORT

An elective right hepatectomy with cholecystectomy and hilar lymph node resection was performed.

RESULTS

Histology showed a central fibrous scar and confirmed a FL-HCC (pT1bN0M0). The resected lymph nodes were tumor-free. Treatment of FL-HCC should consist of complete tumor resection with concurrent lymph node resection +/- orthotopic liver transplantation. Long-term follow-up is advised. A follow-up interval of 3-4 months in the first 2 years after surgical resection can be justified as FL-HCC have a high recurrence rate of more than 50% within 10-33 months.

CONCLUSIONS

Malignancy can be a rare cause of abdominal pain in pediatric patients. An abdominal US is essential to prevent misdiagnosis. Treatment of FL-HCC should consist of R0 tumor resection with concurrent lymphadenectomy +/- orthotopic liver transplantation.

Early Experiences with Triple Immunochemotherapy in Adolescents and Young Adults with High-Risk Fibrolamellar Carcinoma

INTRODUCTION

There are no standard systemic therapies for the treatment of fibrolamellar carcinoma (FLC), as surgery remains the only definitive option. We share our experiences using systemic "triple therapy" (TT) with 5-fluorouracil, interferon, and nivolumab for the treatment of relapsed, refractory, metastatic, or unresectable FLC.

METHODS

Data from all patients who received TT from May 2018 to July 2020 were reviewed to assess response, survival, and toxicity.

RESULTS

A total of 22 patients were treated with TT, of which 14 (median age of 21 years) were evaluable. They received a median of 18 cycles (8-44). At the time of analysis, the median progression-free survival was 9 months (4.5-26), 29% longer than prior to TT, with 5 patients achieving clinical remission, 8 patients stable or improving, and 1 progression. Overall objective response (clinical remission + partial response) was 50% and tumor control rate (clinical remission + partial response + stable disease) was 93%. Two patients withdrew from treatment due to side effects.

DISCUSSION/CONCLUSION

Our early results support TT as a promising medical option to slow disease progression and prolong survival in high-risk patients with FLC. TT can be administered in the outpatient setting and has shown good tolerability. Further longitudinal data is needed to confirm outcomes, especially in patients still early in their treatment.

Pediatric Primary Hepatic Tumors: Diagnostic Considerations

The liver is the third most common site of abdominal tumors in children. This review article aims to summarize current evidence surrounding identification and diagnosis of primary hepatic tumors in the pediatric population based upon clinical presentation, epidemiology, and risk factors as well as classical imaging, histopathological, and molecular diagnostic findings. Readers will be able to recognize the features and distinguish between benign and malignant hepatic tumors within different age groups.

Phase Separation of a PKA Regulatory Subunit Controls cAMP Compartmentation and Oncogenic Signaling

The fidelity of intracellular signaling hinges on the organization of dynamic activity architectures. Spatial compartmentation was first proposed over 30 years ago to explain how diverse G protein-coupled receptors achieve specificity despite converging on a ubiquitous messenger, cyclic adenosine monophosphate (cAMP). However, the mechanisms responsible for spatially constraining this diffusible messenger remain elusive. Here, we reveal that the type I regulatory subunit of cAMP-dependent protein kinase (PKA), RIα, undergoes liquid-liquid phase separation (LLPS) as a function of cAMP signaling to form biomolecular condensates enriched in cAMP and PKA activity, critical for effective cAMP compartmentation. We further show that a PKA fusion oncoprotein associated with an atypical liver cancer potently blocks RIα LLPS and induces aberrant cAMP signaling. Loss of RIα LLPS in normal cells increases cell proliferation and induces cell transformation. Our work reveals LLPS as a principal organizer of signaling compartments and highlights the pathological consequences of dysregulating this activity architecture.

A first case of hepatocellular carcinoma in the baboon (Papio spp.) placenta

We present a case of hepatocellular carcinoma (HCC) in the placenta of healthy baboon (Papio spp.). Grossly, the fetal, maternal, and placental tissues were unremarkable. Histologically, the placenta contained an unencapsulated, poorly demarcated, infiltrative, solidly cellular neoplasm composed of cells that resembled hepatocytes. The neoplastic cells were diffusely positive for vimentin and focally positive for Ae1/Ae3, Arginase -1, glutamine synthetase, and CD10, and negative for ER, vascular markers (CD31 and D240), S100, glypican, C-reactive protein, FABP, desmin, and beta-catenin; INI1 positivity was similar to non-neoplastic tissues. The case likely represents a unique subtype of HCC.

Molecular pathological epidemiology of hepatocellular carcinoma

Molecular pathological epidemiology (MPE) is a new discipline which emerged as an integrated approach of molecular pathology and epidemiology and was introduced for the first time by Professor Shuji Ogino and Professor Meir Stampfer in the year of 2010. MPE studies in hepatocellular carcinoma (HCC) investigate the relationship among risk factors, molecular biomarkers, and initiation, progression, and prognosis of HCC, which can be used for exploring the molecular mechanisms of HCC and for the molecular classification of the high risk population. Type 2 diabetes mellitus (DM) has been confirmed as an established risk factor for HCC, and MPE can be helpful to better understand the underlying molecular mechanisms. On December 20, 2017, the first China-Japan Symposium on HCC-MPE was held successfully in Beijing. HCC-MPE provides the opportunities and challenges to solve some problems of HCC, and I believe that it can be helpful to improve the early diagnosis, molecular typing, personalized prevention and treatment, and prognosis of HCC.