Invasive Ductular Reaction Operates Hepatobiliary Junctions upon Hepatocellular Injury in Rodents and Humans.

Ductular reaction (DR) is observed in virtually all liver diseases in both humans and rodents. Depending on the injury, DR is confined within the periportal area or invades the parenchyma. On severe hepatocellular injury, invasive DR has been proposed to arise for supplying the liver with new hepatocytes. However, experimental data evidenced that DR contribution to hepatocyte repopulation is at the most modest, unless replicative capacity of hepatocytes is abrogated. Herein, we proposed that invasive DR could contribute to operating hepatobiliary junctions on hepatocellular injury. The choline-deficient ethionine-supplemented mouse model of hepatocellular injury and human liver samples were used to evaluate the hepatobiliary junctional role of the invasive form of DR. Choline-deficient ethionine-supplemented-induced DR expanded as biliary epithelium into the lobule and established new junctions with the canaliculi. By contrast, no new ductular-canalicular junctions were observed in mouse models of biliary obstructive injury exhibiting noninvasive DR. Similarly, in humans, an increased number of hepatobiliary junctions were observed in hepatocellular diseases (viral, drug induced, or metabolic) in which DR invaded the lobule but not in biliary diseases (obstruction or cholangitis) in which DR was contained within the portal mesenchyme. In conclusion, our data in rodents and humans support that invasive DR plays a hepatobiliary junctional role to maintain structural continuity between hepatocytes and ducts in disorders affecting hepatocytes.

Correction to: CD73 expression in normal and pathological human hepatobiliopancreatic tissues.

The following information must be added to the published article.

CD73 expression in normal and pathological human hepatobiliopancreatic tissues.

BACKGROUND: The tumor-expressed CD73 ectonucleotidase generates immune tolerance and promotes invasiveness via adenosine production from degradation of AMP. While anti-CD73 blockade treatment is a promising tool in cancer immunotherapy, a characterization of CD73 expression in human hepatobiliopancreatic system is lacking. PATIENTS AND METHODS: CD73 expression was investigated by immunohistochemistry in a variety of non-neoplastic and neoplastic conditions of the liver, pancreas, and biliary tract. RESULTS: CD73 was expressed in normal hepatobiliopancreatic tissues with subcellular-specific patterns of staining: canalicular in hepatocytes, and apical in cholangiocytes and pancreatic ducts. CD73 was present in all hepatocellular carcinoma (HCC), in all pancreatic ductal adenocarcinoma (PDAC), and in the majority of intra and extrahepatic cholangiocellular carcinomas, whereas it was detected only in a subset of pancreatic neuroendocrine neoplasms and almost absent in acinar cell carcinoma. In addition to the canonical pattern of staining, an aberrant membranous and/or cytoplasmic expression was observed in invasive lesions, especially in HCC and PDAC. These two entities were also characterized by a higher extent and intensity of staining as compared to other hepatobiliopancreatic neoplasms. In PDAC, aberrant CD73 expression was inversely correlated with differentiation (p < 0.01) and was helpful to identify isolated discohesive tumor cells. In addition, increased CD73 expression was associated with reduced overall survival (HR 1.013) and loss of E-Cadherin. CONCLUSIONS: Consistent CD73 expression supports the rationale for testing anti-CD73 therapies in patients with hepatobiliopancreatic malignancies. Specific patterns of expression could also be of help in the routine diagnostic workup.

OATPB1/B3 and MRP3 expression in hepatocellular adenoma predicts Gd-EOB-DTPA uptake and correlates with risk of malignancy.

BACKGROUND AND AIMS: Hepatobiliary phase (HBP) Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) has increased the accuracy in differentiating focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA). However, the ability of this technique to distinguish HCA subtypes remains controversial. The aim of this study was to investigate the expression of hepatocyte transporters (OATPB1/B3, MRP2, MRP3) in HCA subtypes, hence to understand their MRI signal intensity on HBP Gd-EOB-DTPA-enhanced MRI. METHODS: By means of immunohistochemistry (IHC), we scored the expression of OATPB1/B3, MRP2 and MRP3, in resected specimens of FNH (n = 40), subtyped HCA (n = 58) and HCA with focal malignant transformation (HCA-HCC, n = 4). Results were validated on a supplementary set of FNH (n = 6), subtyped HCA (n = 17) and HCA-HCC (n = 1) with Gd-EOB-DTPA MR images. RESULTS: All FNH showed a preserved expression of hepatocytes transporters. Beta-catenin-activated HCA (at highest risk of malignant transformation) and HCA-HCC were characterized by preserved/increased OATPB1/B3 expression (predictor of hyperintensity on HBP), as opposed to other HCA subtypes (P < 0.01) that mostly showed OATPB1/B3 absence (predictor of hypointensity on HBP). HCA-HCC showed an additional MRP3 overexpressed profile (P < 0.01). On HBP Gd-EOB-DTPA-enhanced MRI, FNH and HCA signal intensity reflected the profile predicted by their specific OATPB1/B3 tissue expression. The hyperintense vs hypointense HBP signal criterion was able to distinguish all higher risk HCA and HCA-HCC (100% accuracy). CONCLUSIONS: OATPB1/B3 and MRP3 IHC and signal intensity on HBP Gd-EOB-DTPA-enhanced MRI can help to stratify HCA according to their risk of malignant transformation.

[Alagille Syndrome]. / Syndrome d'Alagille.

Alagille syndrome is a rare disorder with low physician awareness. It affects multiple organs and thus patient management involves several medical specialties. It is an autosomal dominant disorder with significant intrafamilial variability. The most frequent clinical manifestations are neonatal jaundice, chronic cholestasis as well as cardiac, ocular and skeletal malformations associated with characteristic facial features. Inherited mutations affect the Notch pathway. Although the molecular basis of Alagille syndrome is well defined, no specific targeted therapy exists.

Le syndrome d'Alagille est une pathologie rare et peu connue dans la pratique médicale. Il s'agit d'une affection multisystémique dont la prise en charge implique plusieurs spécialités médicales. Sa transmission se fait sur un mode autosomique dominant avec néanmoins une expression clinique très variable, au sein d'une même famille chez des sujets présentant une même mutation. Ses manifestations cliniques principales sont un ictère néonatal, une cholestase chronique, une atteinte cardiaque, oculaire, squelettique ainsi qu'un faciès caractéristique. Les diverses mutations identifiées et héritées affectent la voie de signalisation Notch. Bien que la physiopathologie soit actuellement relativement bien définie, aucune thérapie ciblée n'est à l'heure actuelle disponible.

[Primary biliary cholangitis : an update]. / Cholangite biliaire primitive : mise à jour.

Primary biliary cholangitis (PBC) is an autoimmune liver disease which affects primarily women and is characterized by progressive destruction of small intrahepatic bile ducts. Most common symptoms are fatigue and pruritus. Diagnostic hallmarks are cholestasis and positive antimitochondrial antibodies. The first-line therapy is ursodeoxycholic acid (UDCA), with excellent results when started at an early stage. Nevertheless, 30­40 % of patients do not achieve a complete biochemical response with UDCA. In these cases, the adjunction of obeticholic acid can be discussed. Fibrates appear to be a promising alternative. Liver transplantation yields excellent outcomes in advanced cases.

La cholangite biliaire primitive (CBP) est une hépatopathie chronique auto-immune, caractérisée par une destruction progressive des voies biliaires intrahépatiques de petit calibre qui affecte majoritairement les femmes. La CBP se manifeste principalement par une fatigue ainsi qu'un prurit et se traduit au premier plan par une cholestase. L'élément clé du diagnostic est la présence d'autoanticorps antimitochondries. Le traitement de choix est l'acide ursodésoxycholique (AUDC). Il est primordial de le débuter à un stade précoce de la maladie. Néanmoins, 30­40 % des patients ne répondent pas à l'AUDC. L'acide obéticholique peut être envisagé dans cette situation. Les fibrates ont montré des résultats encourageants. Au stade avancé de la maladie, la transplantation hépatique est la seule intervention curative, avec d'excellents résultats.

[Benign focal liver lesions: a clinical, radiological and pathological review]. / Lésions hépatiques focales bénignes : revue clinique, radiologique et pathologique.

Benign focal liver lesions are a heterogeneous group of tumors of different cellular origin. They might develop from mesenchymal cells, hepatocytes or cholangiocytes. They are more often detected due to the increasing number of imaging investigations and the excellent performance of the new ultrasound machines. The imaging findings have to be interpreted while bearing the patient's clinical context in mind. The aim of this review is to discuss the three most frequent benign focal hepatic lesions : hemangioma, focal nodular hyperplasia and hepatocellular adenoma.

Les lésions hépatiques focales bénignes constituent un groupe d'entités hétérogènes d'origines cellulaires différentes, mésenchymateuses, hépatocytaires ou cholangiocytaires. La découverte fortuite d'une ou de plusieurs lésions hépatiques est de plus en plus courante en raison de l'utilisation plus fréquente d'examens d'imagerie et des performances excellentes des nouvelles machines d'échographie. Il est indispensable de toujours interpréter l'imagerie hépatique au regard des données cliniques et biologiques. Le but de cet article est de discuter les trois lésions hépatiques bénignes les plus répandues : l'hémangiome, l'hyperplasie nodulaire focale et l'adénome hépatocel-lulaire.

Morphophenotypic changes in human multistep hepatocarcinogenesis with translational implications.

BACKGROUND & AIMS: Human hepatocarcinogenesis in cirrhosis is thought to be multistep and characterized by a spectrum of nodular lesions, ranging from low to high grade dysplastic nodules (LGDN and HGDN) to early and progressed hepatocellular carcinoma (eHCC and pHCC). The aim of this study was to investigate the morphophenotypical changes of this sequence and their potential translational significance. METHODS: We scored the vascular profile, ductular reaction/stromal invasion and overexpression of five biomarkers (GPC3, HSP70, GS, CHC, and EZH2), in a series of 100 resected nodules (13 LGDN, 16 HGDN, 42 eHCC and 29 small pHCC). RESULTS: The score separated the four groups of nodules as individual entities (p<0.01). In the sequence, biomarker's overexpression progressively increased with parallel decrease of ductular reaction; the vascular remodeling started very early (LGDN) but did not further develop in a proportion of HCC. eHCC was the most heterogeneous entity, with marginal overlap with HGDN and pHCC. Liver environment (fibrosis, etiology) did not impact on the phenotype of the different nodules. A subclass of eHCC (16/42) without evidence of stromal invasion was identified, suggesting a "preinvasive stage" (p<0.05). For diagnosis, the application of four and five biomarkers (rather than the usual three) improved the sensitivity of the assay for the detection of eHCC (76% and 93% vs. 52%); biomarkers in alternative combinations, and also increased the sensitivity of the assay (GS+CHC+EZH2: 76%; GS+CHC+EZH2+HSP70: 90%). CONCLUSIONS: This study supports the multistep nature of human hepatocarcinogenesis, and suggests that eHCC is more heterogeneous than previously thought. This provides further information of the potential translational significance into clinical practice.

Rediscovering Secondary Tumors of the Prostate in the Molecular Era.

Metastatic involvement of the prostate from noncontiguous solid tumors is a rare event occurring by means of vascular dissemination. The reported cases of biopsy and surgical samples with metastatic involvement have increased; however, a comprehensive understanding of secondary tumors of the prostate is currently missing. Metastases to the prostate carry a dismal prognosis and may pose serious diagnostic challenges to both clinicians and pathologists, with crucial therapeutic implications. Secondary tumors of the prostate spread more frequently from the digestive tract, the lung, and the kidney. The integration of clinicoradiologic data with appropriate pathologic and immunohistochemical analyses is essential for the identification and the characterization of secondary tumors of the prostate, whereas molecular analyses could provide additional and complementary information, enabling precise diagnosis and appropriate clinical management. Patients with solitary metastases could benefit from prostatic resection and adjuvant therapy, whereas in cases of disseminated diseases, symptom control may be obtained with palliative procedures. The purpose of this review was to assess the current state of knowledge of secondary tumors involving the prostate gland and to discuss short-term future perspectives, while providing a practical approach to these uncommon conditions for pathologists and oncologists.

TRIP: a pathological score for transarterial chemoembolization resistance individualized prediction in hepatocellular carcinoma.

BACKGROUND & AIMS: Although potentially very useful in optimizing patient selection and follow-up, the individual response to transarterial chemoembolization (TACE) in hepatocellular carcinoma (HCC) is generally unpredictable. The aim of this study was to identify tissue predictors of tumour resistance to TACE for use in clinical practice on pretreatment biopsies. METHODS: We investigated the association of residual tumour in post-TACE-resected HCC with pathological and immunophenotypical features, mainly related to hypoxia and angiogenesis. Comparison of tumour phenotype between post-TACE HCC and both paired pre-TACE biopsies and control TACE-untreated HCC was performed. Cases showing >50% residual tumour (RT) were defined as TACE-resistant. RESULTS: A consecutive series of 108 HCC from 41 patients was studied. Overall, 45/108 (44%) HCC were classified as TACE-resistant. Among these, 32 (71%) and 40 (89%) showed diffuse CD34 vascular staining and negative VEGF staining respectively (p<0.05). The association of these two parameters in a weighted score (TRIP) was able to predict TACE resistance with 81% accuracy, 89% sensitivity and 59% specificity. The effectiveness of TRIP was validated in an independent series of 28 HCC biopsies from patients subsequently treated with TACE and for whom radiological follow-up was available. CONCLUSIONS: This study demonstrates the potential value of pretreatment tumour biopsy as predictors of TACE resistance in HCC.

Gastric Amphicrine Carcinoma Showing Neuroendocrine and Pancreatic Acinar Cell Differentiation. Lesson from a Challenging Case Opening New Perspectives in the Diagnostic Work-Up of Gastric Neuroendocrine Neoplasms.

Amphicrine carcinomas are epithelial neoplasms composed of cells with co-existing exocrine-neuroendocrine phenotype and are challenging lesions from both diagnostic and therapeutic perspectives.Here, we report the case of a 63-year-old male patient with a gastric nodule that was endoscopically biopsied, revealing histological features of a type 3 well-differentiated gastric neuroendocrine tumor (NET). At imaging, the lesion was single and limited to the stomach, but did not present In-111Octreotide uptake, despite SSTR2A immunohistochemical expression. The patient underwent a wedge resection of the gastric wall, with a final pathological diagnosis of amphicrine carcinoma with pancreatic acinar cell and neuroendocrine features (pT1b). Predictive immunohistochemistry showed microsatellite stability and negative HER2 status. Hotspot targeted deep sequencing of 57 genes showed no somatic mutation, in agreement with the low mutational burden reported for gastric amphicrine carcinomas. Due to a low stage of the tumor and the poor performance status of the patient, no additional oncological treatment was administered. The patient was disease-free after 18 months.This unusual case highlights the importance of considering amphicrine carcinoma in the diagnostic work-up of gastric type 3 NET. This can be done by including in the immunohistochemical panel non-neuroendocrine markers, such as the pancreatic acinar cell and glandular ones. Correct pathological diagnosis is pivotal to determine the appropriate staging (NET vs exocrine one) for surgical and oncological management.

The first comprehensive genomic characterization of rectal squamous cell carcinoma.

BACKGROUND: Rectal cancers represent 35% of colorectal cancers; 90% are adenocarcinomas, while squamous cell carcinoma accounts for 0.3% of them. Given its rarity, little is known concerning its pathogenesis, molecular profile and therapeutic management. The current treatment trend is to treat rectal squamous cell carcinoma by analogy to anal squamous cell carcinoma with definitive chemo-radiotherapy, setting aside surgery in case of local recurrence. METHODS: We performed an in-depth genomic analysis (next-generation sequencing, copy number variation, and human papilloma virus characterization) on 10 rectal squamous cell carcinoma samples and compared them in silico to those of anal squamous cell carcinoma and rectal adenocarcinoma. RESULTS: Rectal squamous cell carcinoma shows 100% HPV positivity. It has a mutational (PIK3CA, PTEN, TP53, ATM, BCL6, SOX2) and copy number variation profile (3p, 10p, 10q, 16q deletion and 1q, 3q, 5p, 8q, 20p gain) similar to anal squamous cell carcinoma. PI3K/Akt/mTOR is the most commonly affected signaling pathway similarly to anal squamous cell carcinoma. Most commonly gained or lost genes seen in rectal adenocarcinoma (FLT3, CDX2, GNAS, BCL2, SMAD4, MALT1) are not found in rectal squamous cell carcinoma. CONCLUSION: This study presents the first comprehensive genomic characterization of rectal squamous cell carcinoma. We confirm the existence of this rare histology and its molecular similarity with anal squamous cell carcinoma. This molecular proximity confirms the adequacy of therapeutic management based on histology and not localization, suggesting that rectal squamous cell carcinoma should be treated like anal squamous cell carcinoma and not as a rectal adenocarcinoma.

Does Mixed Neuroendocrine-Nonneuroendocrine Neoplasm (MiNEN) of the Parathyroid Gland Exist? First Description of a Possible Case.

We describe the histological, histochemical, and immunohistochemical features of an unusual neoplasm of the parathyroid gland showing the histologic criteria of a mixed neuroendocrine-nonneuroendocrine neoplasm (MiNEN). To the best of our knowledge, this is the first report of such a tumor. A 43-year old male presented with acute and severe abdominal pain due to acute pancreatitis. On physical examination a painless lump in the right neck was detected and laboratory analyses revealed hyperparathyroidism (parathormone: 146 pmol/L, normal range 1.05-6.83) and hypercalcemia (calcium level: 3.02 mg/dL, normal range 2.25-2.5), which fell to 2.55 mg/dL after parathyroidectomy. Histologically, the tumor was a parathyroid carcinoma associated with a mucous secreting adenocarcinoma also confirmed by histochemical (Alcian blue-periodic acid Schiff) and immunohistochemical stainings. The present case expands the spectrum of MiNENs that can be found in endocrine organs.

CD73 expression in normal, hyperplastic, and neoplastic thyroid: a systematic evaluation revealing CD73 overexpression as a feature of papillary carcinomas.

CD73 converts AMP to adenosine, an immunosuppressive metabolite that promotes tumorigenesis. This study presents a systematic evaluation of CD73 expression in benign, hyperplastic, and neoplastic thyroid. CD73 expression was assessed by immunohistochemistry in 142 thyroid samples. CD73 was expressed in normal thyroid (3/6) and goiter (5/6), with an apical pattern and mild intensity. Apical and mild CD73 expression was also present in oncocytic cell adenomas/carcinomas (9/10; 5/8) and in follicular adenomas/carcinomas (12/18; 23/27). In contrast, papillary thyroid carcinomas featured extensive and intense CD73 staining (49/50) (vs. normal thyroid/goiter, p < 0.001). Seven of nine anaplastic carcinomas were CD73-positive with heterogeneous extensiveness of staining. Medullary and poorly differentiated carcinomas were mostly CD73-negative (1/6; 2/2). These results were corroborated by NT5E mRNA profiling. Papillary carcinomas feature enhanced CD73 protein and mRNA expression with distinct and intense staining, more pronounced in the invasive fronts of the tumors.

Updates in the diagnosis of combined hepatocellular-cholangiocarcinoma.

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a rare primary liver carcinoma showing variable degrees of differentiation toward hepatocellular and cholangiocellular carcinoma. Its great heterogeneity in term of morphology, immunophenotype, molecular, radiological and clinical features represents a challenge still to overcome. The multidisciplinary 2018 International Consensus on the nomenclature of cHCC-CCA allowed to define key issues of this entity. Here we review the historical controversies of cHCC-CCA, resume the key elements of the 2018 consensus, now incorporated in the 2019 WHO classification, and propose a short survival guide to help surgical pathologists facing cHCC-CCA in their routine workup.

Histologic parameter score does not predict short-term survival in severe alcoholic hepatitis.

BACKGROUND AND AIM: The alcoholic hepatitis histologic score has been proposed as a new prognostic tool to assess the risk of death in alcoholic hepatitis. We aimed to evaluate its prognostic value in patients with severe alcoholic hepatitis. METHODS: Liver biopsies were analysed independently by two pathologists according to the alcoholic hepatitis histologic score. The Laennec staging system was also used to evaluate fibrosis. RESULTS: One hundred and seven patients were included, and 89% of the patients received corticosteroids. The alcoholic hepatitis histologic score was available in 105 patients. Histologic scoring showed mild, moderate and severe scores in 10, 29 and 66 patients, respectively. Laennec staging was available for 53 patients, among whom 49 had cirrhosis, including 7 with Laennec 4A, 15 with 4B and 27 with 4C. Survival rates in mild, moderate and severe alcoholic hepatitis histologic score groups were 90%, 72% and 69% at 28 days (p = 0.6), 80%, 52% and 63% at 3 months (p = 0.3), and 70%, 41% and 58% at 6 months (p = 0.3), respectively. Within the alcoholic hepatitis histologic score, fibrosis demonstrated the best interobserver reproducibility (agreement = 100%, Κ = 1.00). Compared to patients with Laennec 4B or 4C cirrhosis, survival rates for patients without cirrhosis or with Laennec 4A cirrhosis were 100% vs 83% at 28 days (p = 0.16), 91% vs 68% at 3 months (p = 0.13), and 82% vs 64% at 6 months (p = 0.2), respectively. In multivariate analysis adjusted for age and for model for end-stage liver disease score, the alcoholic hepatitis histologic score and Laennec stage were not associated with 6-month mortality. CONCLUSIONS: The alcoholic hepatitis histologic score is not predictive of short-term survival in this cohort of patients with severe alcoholic hepatitis.

Gallbladder Mixed Neuroendocrine-Non-neuroendocrine Neoplasm (MiNEN) Arising in Intracholecystic Papillary Neoplasm: Clinicopathologic and Molecular Analysis of a Case and Review of the Literature.

Mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) of the gallbladder are generally composed of adenocarcinoma and neuroendocrine carcinoma (NEC). Rare cases associated with intracholecystic papillary neoplasm (ICPN) have been reported. Although recent molecular data suggest that the different components of digestive MiNENs originate from a common precursor stem cell, this aspect has been poorly investigated in gallbladder MiNENs. We describe the clinicopathologic and molecular features of a MiNEN composed of ICPN, adenocarcinoma, and NEC. A 66-year-old woman presented with severe abdominal pain. She underwent radical cholecystectomy and an intracholecystic mass was found. Histologically, it was composed of ICPN associated with adenocarcinoma and large cell neuroendocrine carcinoma (LCNEC). The three components were positive for DNA repair proteins and p53. EMA was positive in the ICPN and adenocarcinoma components, while it was negative in the LCNEC. Heterogeneous expression of Muc5AC, cytokeratin 20, and CDX2 was only observed in the ICPN component. Cytokeratin 7 was diffusely positive in both adenocarcinoma and LCNEC components, while it was heterogeneously expressed in the ICPN. The copy number variation analysis showed overlapping results between the adenocarcinoma and LCNEC components with some minor differences with the ICPN component. The three tumor components showed the same mutation profile including TP53 mutation c.700T > C (p. Tyr234His), without mutations in other 51 genes known to be frequently altered in cancer pathogenesis and growth. This finding may support the hypothesis of a monoclonal origin of the different tumor components. We have also performed a review of the literature on gallbladder MiNENs.

Exploring the Prognostic Role of Ki67 Proliferative Index in Merkel Cell Carcinoma of the Skin: Clinico-Pathologic Analysis of 84 Cases and Review of the Literature.

The exact prediction of outcome of patients with Merkel cell carcinoma (MCC) of the skin is difficult to determine, although several attempts have been made to identify clinico-pathologic prognostic factors. The Ki67 proliferative index is a well-known marker routinely used to define the prognosis of patients with neuroendocrine neoplasms. However, its prognostic value has been poorly investigated in MCC, and available published results are often contradictory mainly because restricted to small series in the absence of standardized methods for Ki67 evaluation. For this reason, we explored the potential prognostic role of Ki67 proliferative index in a large series of MCCs using the WHO standardized method of counting positive cells in at least 500 tumor cells in hot spot areas on camera-captured printed images. In addition, since MCC may be considered as the cutaneous counterpart of digestive neuroendocrine carcinomas (NECs), we decided to stratify MCCs using the available and efficient Ki67 threshold of 55%, which was found prognostic in digestive NECs. This choice was also supported by the Youden index analysis. In addition, we analyzed the prognostic value of other clinico-pathologic parameters using both univariate and multivariate analysis. Ki67 index appeared significantly associated with prognosis at univariate analysis together with stage IV, lack of MCPyV, and p63 expression, but not at the multivariate analysis, where survival resulted independently influenced by p63 expression and tumor stage, only.