Nf1 deficiency modulates the stromal environment in the pretumorigenic rat mammary gland.

Background: Neurofibromin, coded by the NF1 tumor suppressor gene, is the main negative regulator of the RAS pathway and is frequently mutated in various cancers. Women with Neurofibromatosis Type I (NF1)-a tumor predisposition syndrome caused by a germline NF1 mutation-have an increased risk of developing aggressive breast cancer with poorer prognosis. The mechanism by which NF1 mutations lead to breast cancer tumorigenesis is not well understood. Therefore, the objective of this work was to identify stromal alterations before tumor formation that result in the increased risk and poorer outcome seen among NF1 patients with breast cancer. Approach: To accurately model the germline monoallelic NF1 mutations in NF1 patients, we utilized an Nf1-deficient rat model with accelerated mammary development before presenting with highly penetrant breast cancer. Results: We identified increased collagen content in Nf1-deficient rat mammary glands before tumor formation that correlated with age of tumor onset. Additionally, gene expression analysis revealed that Nf1-deficient mature adipocytes in the rat mammary gland have increased collagen expression and shifted to a fibroblast and preadipocyte expression profile. This alteration in lineage commitment was also observed with in vitro differentiation, however, flow cytometry analysis did not show a change in mammary adipose-derived mesenchymal stem cell abundance. Conclusion: Collectively, this study uncovered the previously undescribed role of Nf1 in mammary collagen deposition and regulating adipocyte differentiation. In addition to unraveling the mechanism of tumor formation, further investigation of adipocytes and collagen modifications in preneoplastic mammary glands will create a foundation for developing early detection strategies of breast cancer among NF1 patients.

Association Between MR Elastography Liver Stiffness and Histologic Liver Fibrosis in Children and Young Adults With Autoimmune Liver Disease.

BACKGROUND. Liver fibrosis is an important clinical endpoint of the progression of autoimmune liver disease (AILD); its monitoring would benefit from noninvasive imaging tools. OBJECTIVE. The purpose of this study was to assess the relationship between MR elastography (MRE) liver stiffness measurements and histologic liver fibrosis, as well as to evaluate the performance of MRE and biochemical-based clinical markers for stratifying histologic liver fibrosis severity, in children and young adults with AILD. METHODS. This retrospective study used an existing institutional registry of children and young adults diagnosed with AILD (primary sclerosing cholangitis [PSC], autoimmune sclerosing cholangitis [ASC], or autoimmune hepatitis [AIH]). The registry was searched to identify patients who underwent both a research abdominal 1.5-T MRI examination that included liver MRE (performed for registry enrollment) and a clinically indicated liver biopsy within 6 months of that examination. MRE used a 2D gradient-recalled echo sequence. One analyst measured mean liver shear stiffness (in kilopascals) for each examination. Laboratory markers of liver fibrosis (aspartate aminotransferase-to-platelet ratio index [APRI] and fibrosis-4 [FIB-4] score) were recorded. For investigational purposes, one pathologist, blinded to clinical and MRI data, determined histologic Metavir liver fibrosis stage. The Spearman rank order correlation coefficient was calculated between MRE liver stiffness and Metavir liver fibrosis stage. ROC analysis was used to evaluate diagnostic performance for identifying advanced fibrosis (i.e., differentiating Metavir F0-F1 from F2-F4 fibrosis), and sensitivity and specificity were calculated using the Youden index. RESULTS. The study included 46 patients (median age, 16.6 years [IQR, 13.7-17.8 years]; 20 female patients, 26 male patients); 12 had PSC, 10 had ASC, and 24 had AIH. Median MRE liver stiffness was 2.9 kPa (IQR, 2.2-4.0 kPa). MRE liver stiffness and Meta-vir fibrosis stage showed strong positive correlation (ρ = 0.68). For identifying advanced liver fibrosis, MRE liver stiffness had an AUC of 0.81, with sensitivity of 65.4% and specificity of 90.0%; APRI had an AUC of 0.72, with sensitivity of 64.0% and specificity of 80.0%; and FIB-4 score had an AUC of 0.71, with sensitivity of 60.0% and specificity of 85.0%. CONCLUSION. MRE liver stiffness measurements were associated with histologic liver fibrosis severity. CLINICAL IMPACT. The findings support a role for MRE in noninvasive monitoring of liver stiffness, a surrogate for fibrosis, in children and young adults with AILD. TRIAL REGISTRATION. ClinicalTrials.gov NCT03175471.

Histologic Severity of Nonalcoholic Fatty Liver Disease Associates with Reduced Bone Mineral Density in Children.

BACKGROUND: Lower whole body bone mineral density (BMD) has been reported in children with nonalcoholic fatty liver disease (NAFLD), but potential mediators remain uncertain. AIMS: To assess BMD at multiple skeletal sites in children with confirmed NAFLD and controls with obesity, adjusting for known determinants of BMD, and examine potential mediators. METHODS: We assessed age-, sex-, and race-specific, and height-adjusted BMD z-scores of whole body, lumbar spine, hip, femoral neck and forearm by dual-energy-x-ray absorptiometry in 79 children, 8-19 years old: 46 with biopsy-confirmed NAFLD [29 steatohepatitis (NASH)/17 fatty liver (NAFL)] and 33 controls without liver disease. We compared BMD z-scores by multivariable regression, adjusting for known BMD determinants and potential mediators (inflammatory and insulin resistance measures). RESULTS: Unadjusted mean BMD z-scores in NAFLD were similar to controls, but significantly lower in NASH vs. NAFL at all sites. After covariate adjustment, mean forearm BMD z-score was higher in NAFL (ß 0.60 ± SE 0.30, p < 0.05) and lower in NASH (ß - 0.49 ± SE 0.26, p = 0.06) vs. controls (p = 0.002 for group), with similar trends at whole body and total hip; hs-CRP negatively associated with whole body and forearm BMD z-scores (p < 0.05), while visceral fat area negatively associated with femoral neck (p < 0.05). Only three children had clinically low whole body BMD z-scores (< - 2), one per group (control, NAFL and NASH). CONCLUSIONS: NASH, but not NAFL, may be associated with increased risk of reduced BMD in children. Systemic inflammation, independent of body composition and load bearing, may mediate reduction in BMD in NASH.

Customized Postoperative Therapy Improves Bile Drainage in Biliary Atresia: A Single Center Preliminary Report.

BACKGROUND: Controversies in management of biliary atresia (BA) after hepatoportoenterostomy (HPE) lead to variable treatment protocols. We implemented standardized medical management after HPE, customizing the use of antibiotics and corticosteroids based on patient-specific factors. METHODS: In this retrospective analysis, 20 consecutive infants underwent HPE for BA and were compared to a historical cohort. Analysis of successful biliary drainage 3 months after HPE (defined as serum total bilirubin <2 mg/dL) was the primary endpoint; survival with native liver at 2 years was the secondary endpoint. RESULTS: Sixteen of 20 (80%) infants had successful bile drainage, compared to 8 of 20 (40%) infants in the historical cohort (P = 0.0225). Sixteen of 20 patients in the new protocol have reached 2 years of age or required liver transplantation. Among the sixteen, 11 (68.8%) are alive with native livers versus 10 of 20 (50%) in the historical cohort (P = 0.0970). CONCLUSION: This preliminary report suggests the potential benefit of tailored use of postoperative antibiotics and corticosteroids in improving biliary drainage after HPE. LEVEL OF EVIDENCE: III.

Serum Matrix Metalloproteinase 7 Is a Diagnostic Biomarker of Biliary Injury and Fibrosis in Pediatric Autoimmune Liver Disease.

In autoimmune liver disease (AILD), including autoimmune hepatitis (AIH), primary sclerosing cholangitis (PSC), and overlap syndrome of AIH and PSC (ASC), the presence of biliary injury portends a worse prognosis. We studied serum matrix metalloproteinase 7 (sMMP7) as a biomarker for pediatric sclerosing cholangitis (SC). We prospectively enrolled 54 children (median age, 16 years) with AILD (AIH, n = 26; ASC, n = 16; and PSC, n = 12) at our center. The sMMP7 concentrations were higher in patients with SC compared to those without cholangiopathy (P < 0.001). An sMMP7 concentration >23.7 ng/mL had a sensitivity and specificity of 79% and 96%, respectively, and outperformed alkaline phosphatase (ALP) and gamma-glutamyltransferase (GGT) in segregating patients with SC. Serum concentrations correlated with liver gene expression levels for MMP7 (r = 0.70; P < 0.001). Using immunofluorescence, MMP7 was localized primarily to the cholangiocytes of patients with SC. In 46 subjects with liver biopsy available for blinded review, elevation in sMMP7 concentrations segregated with the presence of lymphocytic and neutrophilic cholangitis and periductal fibrosis and correlated with Ishak, Ludwig, and Nakanuma scoring systems. Liver stiffness measured by magnetic resonance elastography also correlated with sMMP7 concentrations (r = 0.56; P < 0.01). Using magnetic resonance cholangiopancreatography plus (MRCP+), sMMP7 in 34 patients correlated with the number of biliary dilatations (r = 0.54; P < 0.01) and strictures (r = 0.56; P < 0.01). MMP7 as a marker of biliary injury was validated in an independent cohort of children with ulcerative colitis. Higher sMMP7 concentrations also correlated with a history of SC-related complication. Conclusion: MMP7 is a promising biomarker for pediatric SC that diagnostically outperforms ALP and GGT. sMMP7 may directly reflect biliary injury and fibrosis, the main drivers of disease progression in SC.

Poorly differentiated thyroid carcinoma of childhood and adolescence: a distinct entity characterized by DICER1 mutations.

Poorly differentiated thyroid carcinomas (PDTC) in young individuals are rare and their clinical and histopathologic features, genetic mechanisms, and outcomes remain largely unknown. Here, we report a detailed characterization of a series of six PDTC in patients ≤21 years old defined by Turin diagnostic criteria studied for mutations and gene fusions characteristic of thyroid cancer using targeted next-generation sequencing (NGS) and whole-exome sequencing (WES). All tumors had solid, insular, or trabecular growth pattern and high mitotic rate, and five out of six tumors showed tumor necrosis. Targeted NGS assay identified somatic mutations in the DICER1 gene in five of six (83%) tumors, all of which were "hotspot" mutations encoding the metal-ion binding sites of the RNase IIIb domain of DICER1. WES was performed in five cases which confirmed all hotspot mutations and detected two tumors with additional inactivating DICER1 alterations. Of these two, one was a germline pathogenic DICER1 variant and the other had loss of heterozygosity for DICER1. No other mutations or gene fusions characteristic of adult well-differentiated thyroid cancer and PDTC (BRAF, RAS, TERT, RET/PTC, and other) were detected. On follow-up, available for five patients, three patients died of disease 8-24 months after diagnosis, whereas two were alive with no disease. The results of our study demonstrate that childhood- and adolescent-onset PDTC are genetically distinct from adult-onset PDTC in that they are strongly associated with DICER1 mutations and may herald DICER1 syndrome in a minority. As such, all young persons with PDTC may benefit from genetic counseling. Furthermore, their clinically aggressive behavior contrasts sharply with the indolent nature of the great majority of thyroid tumors with DICER1 mutations reported to date.

Congenital Portosystemic Shunts in Children: Associations, Complications, and Outcomes.

BACKGROUND: Congenital portosystemic shunt (CPSS) is a rare malformation in which splanchnic venous flow bypasses the liver. CPSS is associated with other congenital anomalies and syndromes and can be associated with life-threatening complications. CPSS and their management remain underreported in the literature. Here, we review the clinical characteristics, management, and outcomes of a cohort of children and young adults with CPSS from two pediatric centers. METHODS: Cases of CPSS from Cincinnati Children's Hospital Medical Center and C.S. Mott Children's Hospital were reviewed to define CPSS anatomy, associated anomalies, complications, interventions, and outcomes. The imaging features and histopathology of liver lesions were characterized in detail. RESULTS: A total of 11 cases were identified. Median age was 10 years (range 0-26); 8 (73%) cases were female. Associated anomalies included six patients with heterotaxy (55%), five patients with congenital heart disease (45%), three patients with Turner syndrome (27%), and two patients with omphalocele, exstrophy, imperforate anus, spinal defects (OEIS) complex (18%). Eight (73%) cases had hyperammonemia ± encephalopathy. A 4-month-old presented with hepatopulmonary syndrome, and 12-year-old presented with pulmonary hypertension. Eight patients (73%) had liver lesions including five with premalignant adenomas and three with well-differentiated hepatocellular carcinoma (HCC). Four children underwent successful CPSS occlusion/ligation. Three children underwent liver transplant (2) or resection (1) for HCC without recurrence at extended follow-up. CONCLUSIONS: CPSS is associated with multiple anomalies (heterotaxy, congenital heart disease) and syndromes (Turner syndrome). CPSS liver lesions should be very carefully evaluated due to risk of premalignant adenomas and HCC. Serious complications of CPSS can occur at a young age but can be managed endovascularly or with open surgery.

Community Socioeconomic Deprivation and Nonalcoholic Fatty Liver Disease Severity.

BACKGROUND AND OBJECTIVES: Nonalcoholic fatty liver disease (NAFLD) is linked to obesity. Obesity is associated with lower socioeconomic status (SES). An independent link between pediatric NAFLD and SES has not been elucidated. The objective of this study was to evaluate the distribution of socioeconomic deprivation, measured using an area-level proxy, in pediatric patients with known NAFLD and to determine whether deprivation is associated with liver disease severity. METHODS: Retrospective study of patients <21 years with NAFLD, followed from 2009 to 2018. The patients' addresses were mapped to census tracts, which were then linked to the community deprivation index (CDI; range 0--1, higher values indicating higher deprivation, calculated from six SES-related variables available publicly in US Census databases). RESULTS: Two cohorts were evaluated; 1 with MRI (magnetic resonance imaging) and/or MRE (magnetic resonance elastography) findings indicative of NAFLD (n = 334), and another with biopsy-confirmed NAFLD (n = 245). In the MRI and histology cohorts, the majority were boys (66%), non-Hispanic (77%-78%), severely obese (79%-80%), and publicly insured (55%-56%, respectively). The median CDI for both groups was 0.36 (range 0.15-0.85). In both cohorts, patients living above the median CDI were more likely to be younger at initial presentation, time of MRI, and time of liver biopsy. MRI-measured fat fraction and liver stiffness, as well as histologic characteristics were not different between the high- and low-deprivation groups. CONCLUSIONS: Children with NAFLD were found across the spectrum of deprivation. Although children from more deprived neighborhoods present at a younger age, they exhibit the same degree of NAFLD severity as their peers from less deprived areas.

Molecular, endoscopic, histologic, and circulating biomarker-based diagnosis of eosinophilic gastritis: Multi-site study.

BACKGROUND: Eosinophilic gastritis (EG) is a clinicopathologic disorder with marked gastric eosinophilia and clinical symptoms. There is an unmet need among patients with EG for more precise diagnostic tools. OBJECTIVE: We aimed to develop tissue- and blood-based diagnostic platforms for EG. METHODS: Patients with EG and control subjects without EG were enrolled across 9 Consortium of Eosinophilic Gastrointestinal Disease Researchers-associated sites. An EG Diagnostic Panel (EGDP; gastric transcript subset) and EG blood biomarker panel (protein multiplex array) were analyzed. EGDP18 scores were derived from the expression of 18 highly dysregulated genes, and blood EG scores were derived from dysregulated cytokine/chemokine levels. RESULTS: Gastric biopsy specimens and blood samples from 185 subjects (patients with EG, n = 74; control subjects without EG, n = 111) were analyzed. The EGDP (1) identified patients with active EG (P < .0001, area under the curve ≥ 0.95), (2) effectively monitored disease activity in longitudinal samples (P = .0078), (3) highly correlated in same-patient samples (antrum vs body, r = 0.85, P < .0001), and (4) inversely correlated with gastric peak eosinophil levels (r = -0.83, P < .0001), periglandular circumferential collars (r = -0.73, P < .0001), and endoscopic nodularity (r = -0.45, P < .0001). For blood-based platforms, eotaxin-3, thymus and activation-regulated chemokine, IL-5, and thymic stromal lymphopoietin levels were significantly increased. Blood EG scores (1) distinguished patients with EG from control subjects without EG (P < .0001, area under the curve ≥ 0.91), (2) correlated with gastric eosinophil levels (plasma: r = 0.72, P = .0002; serum: r = 0.54, P = .0015), and (3) inversely correlated with EGDP18 scores (plasma: r = -0.64, P = .0015; serum: r = -0.46, P = .0084). Plasma eotaxin-3 levels strongly associated with gastric CCL26 expression (r = 0.81, P < .0001). CONCLUSION: We developed tissue- and blood-based platforms for assessment of EG and uncovered robust associations between specific gastric molecular profiles and histologic and endoscopic features, providing insight and clinical readiness tools for this emerging rare disease.

Focal liver lesions following Fontan palliation of single ventricle physiology: A radiology-pathology case series.

PURPOSE: Patients who have undergone Fontan palliation of single ventricle physiology congenital heart disease are prone to developing focal liver lesions. In our experience, the variety of lesions occurring in this population is greater than that described in the literature. The purpose of this study was to describe the breadth of biopsy-proven liver lesions in patients post-Fontan palliation of single ventricle physiology cared for at our institution. METHODS: We retrospectively identified patients who had previously undergone the Fontan operation and had a focal liver lesion biopsied between January 2000 and June 2018. Medical records were reviewed for lesion pathology, background liver findings, pertinent laboratory data, and demographic data. CT and MRI images were reviewed to describe imaging findings of the reported lesions. RESULTS: Twelve patients met inclusion criteria; 58% (7/12) of which were female. Fifteen lesions were biopsied including four macroregenerative/benign hepatocellular hyperplastic nodules, two hepatocellular adenomas, two hepatocellular carcinomas, two intrahepatic cholangiocarcinoma (in the same patient), one venous malformation, and one focus of vascularized scar tissue. Two additional lesions in patients postcardiac transplant were posttransplant lymphoproliferative disorder. CONCLUSION: Patients who have undergone Fontan palliation of single ventricle physiology are prone to develop a variety of liver lesions, both benign and malignant.

Pan-Trk Immunohistochemistry Identifies NTRK Rearrangements in Pediatric Mesenchymal Tumors.

Activating neurotrophic receptor kinase (NTRK) fusions define certain pediatric mesenchymal tumors, including infantile fibrosarcoma and cellular mesoblastic nephroma. Traditionally, molecular confirmation of these fusions has included either fluorescent in situ hybridization for ETV6 rearrangements or reverse-transcriptase polymerase chain reaction for the classic ETV6-NTRK3 fusion. However, these methods overlook variant NTRK rearrangements, which are increasingly appreciated as recurrent events in a subset of pediatric mesenchymal tumors. New therapeutic agents successfully target these fusions and may prevent morbid surgeries in very young children, making recognition of tumors harboring NTRK rearrangements of increasing importance. We evaluated the performance of immunohistochemical (IHC) staining using pan-Trk and TrkA antibodies in 79 pediatric mesenchymal tumors. Negative controls included pediatric mesenchymal tumors not harboring (n=28) or not expected to harbor (n=22) NTRK fusions. NTRK rearrangements were detected predominantly by DNA-based next-generation sequencing assays, specifically UW OncoPlex and UCSF500 Cancer Gene Panel. Pan-Trk IHC (EPR17341) was 97% sensitive and 98% specific for the presence of an NTRK rearrangement, and TrkA IHC (EP1058Y) was 100% sensitive and 63% specific for the presence of an NTRK rearrangement. Tumors with NTRK1 or NTRK2 rearrangements showed cytoplasmic staining, whereas tumors with NTRK3 rearrangements showed nuclear +/- cytoplasmic staining. We conclude that pan-Trk IHC is a highly sensitive and specific marker for NTRK rearrangements in pediatric mesenchymal tumors.

Peroxisomal ß-oxidation regulates whole body metabolism, inflammatory vigor, and pathogenesis of nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD), a metabolic predisposition for development of hepatocellular carcinoma (HCC), represents a disease spectrum ranging from steatosis to steatohepatitis to cirrhosis. Acox1, a rate-limiting enzyme in peroxisomal fatty acid ß-oxidation, regulates metabolism, spontaneous hepatic steatosis, and hepatocellular damage over time. However, it is unknown whether Acox1 modulates inflammation relevant to NAFLD pathogenesis or if Acox1-associated metabolic and inflammatory derangements uncover and accelerate potential for NAFLD progression. Here, we show that mice with a point mutation in Acox1 (Acox1Lampe1) exhibited altered cellular metabolism, modified T cell polarization, and exacerbated immune cell inflammatory potential. Further, in context of a brief obesogenic diet stress, NAFLD progression associated with Acox1 mutation resulted in significantly accelerated and exacerbated hepatocellular damage via induction of profound histological changes in hepatocytes, hepatic inflammation, and robust upregulation of gene expression associated with HCC development. Collectively, these data demonstrate that ß-oxidation links metabolism and immune responsiveness and that a better understanding of peroxisomal ß-oxidation may allow for discovery of mechanisms central for NAFLD progression.

Diagnostic Performance of MR Elastography for Liver Fibrosis in Children and Young Adults with a Spectrum of Liver Diseases.

Purpose To assess the diagnostic performance of magnetic resonance (MR) elastography-derived liver stiffness to detect liver fibrosis in a pediatric and young adult population with a spectrum of liver diseases. Materials and Methods This retrospective study included patients younger than 21 years of age who underwent MR elastography and liver biopsy within 3 months of one another between January 2012 and September 2016 for indications other than liver transplantation or Fontan palliation of congenital heart disease. MR elastography examinations were reprocessed by a single observer, blinded to pathologic findings. Pathology specimens were reviewed by a single pathologist who scored steatosis (lipid in ≥ 5% of hepatocytes) and staged fibrosis. Receiver operating characteristic (ROC) curves were used to assess diagnostic performance. Results A total of 86 patients, 49 (57%) male with a median age of 14.2 years (range, 0.3-20.6 years), were included. Fifty-one patients (59.3%) had Ludwig stage 2 or higher fibrosis; 44 patients (51.2%) had hepatic steatosis. The area under the ROC curve for Ludwig stage 0-1 versus stage 2 or higher fibrosis was 0.70 (95% confidence interval [CI]: 0.59, 0.81) for the whole population and was significantly lower for patients with steatosis versus those without (0.53 [95% CI: 0.35, 0.71] vs 0.82 [95% CI: 0.67, 0.96], P = .014). Optimal stiffness cut-offs for the entire population were 2.27 kPa with 68.6% sensitivity (95% CI: 57.2%, 80.1%) and 74.3% specificity (95% CI: 63.5%, 85.1%) or 1.67 kPa with 35.3% sensitivity (95% CI: 23.5%, 47.1%) and 91.4% specificity (95% CI: 84.5%, 98.3%). Conclusion In children and young adults, MR elastography performs significantly better for distinguishing stage 0-1 versus stage 2 or higher fibrosis in patients without steatosis than in those with steatosis. This suggests a confounding effect of steatosis or inflammation in the population with nonalcoholic fatty liver disease. © RSNA, 2018.

Thermoneutral housing exacerbates nonalcoholic fatty liver disease in mice and allows for sex-independent disease modeling.

Nonalcoholic fatty liver disease (NAFLD), a common prelude to cirrhosis and hepatocellular carcinoma, is the most common chronic liver disease worldwide. Defining the molecular mechanisms underlying the pathogenesis of NAFLD has been hampered by a lack of animal models that closely recapitulate the severe end of the disease spectrum in humans, including bridging hepatic fibrosis. Here we demonstrate that a novel experimental model employing thermoneutral housing, as opposed to standard housing, resulted in lower stress-driven production of corticosterone, augmented mouse proinflammatory immune responses and markedly exacerbated high-fat diet (HFD)-induced NAFLD pathogenesis. Disease exacerbation at thermoneutrality was conserved across multiple mouse strains and was associated with augmented intestinal permeability, an altered microbiome and activation of inflammatory pathways that are associated with the disease in humans. Depletion of Gram-negative microbiota, hematopoietic cell deletion of Toll-like receptor 4 (TLR4) and inactivation of the IL-17 axis resulted in altered immune responsiveness and protection from thermoneutral-housing-driven NAFLD amplification. Finally, female mice, typically resistant to HFD-induced obesity and NAFLD, develop full disease characteristics at thermoneutrality. Thus, thermoneutral housing provides a sex-independent model of exacerbated NAFLD in mice and represents a novel approach for interrogation of the cellular and molecular mechanisms underlying disease pathogenesis.

3D printed pathological sectioning boxes to facilitate radiological-pathological correlation in hepatectomy cases.

Radiogenomics promises to identify tumour imaging features indicative of genomic or proteomic aberrations that can be therapeutically targeted allowing precision personalised therapy. An accurate radiological-pathological correlation is critical to the process of radiogenomic characterisation of tumours. An accurate correlation, however, is difficult to achieve with current pathological sectioning techniques which result in sectioning in non-standard planes. The purpose of this work is to present a technique to standardise hepatic sectioning to facilitateradiological-pathological correlation. We describe a process in which three-dimensional (3D)-printed specimen boxes based on preoperative cross-sectional imaging (CT and MRI) can be used to facilitate pathological sectioning in standard planes immediately on hepatic resection enabling improved tumour mapping. We have applied this process in 13 patients undergoing hepatectomy and have observed close correlation between imaging and gross pathology in patients with both unifocal and multifocal tumours.

FXR-Gankyrin axis is involved in development of pediatric liver cancer.

The development of hepatoblastoma (HBL) is associated with failure of hepatic stem cells (HSC) to differentiate into hepatocytes. Despite intensive investigations, mechanisms of the failure of HSC to differentiate are not known. We found that oncogene Gankyrin (Gank) is involved in the inhibition of differentiation of HSC via triggering degradation of tumor suppressor proteins (TSPs) Rb, p53, C/EBPα and HNF4α. Our data show that the activation of a repressor of Gank, farnesoid X receptor, FXR, after initiation of liver cancer by Diethylnitrosamine (DEN) prevents the development of liver cancer by inhibiting Gank and rescuing tumor suppressor proteins. We next analyzed FXR-Gank-Tumor suppressor pathways in a large cohort of HBL patients which include 6 controls and 53 HBL samples. Systemic analysis of these samples and RNA-Seq approach revealed that the FXR-Gank axis is activated; markers of hepatic stem cells are dramatically elevated and hepatocyte markers are reduced in HBL samples. In the course of these studies, we found that RNA binding protein CUGBP1 is a new tumor suppressor protein which is reduced in all HBL samples. Therefore, we generated CUGBP1 KO mice and examined HBL signatures in the liver of these mice. Micro-array studies revealed that the HBL-specific molecular signature is developed in livers of CUGBP1 KO mice at very early ages. Thus, we conclude that FXR-Gank-TSPs-Stem cells pathway is a key determinant of liver cancer in animal models and in pediatric liver cancer. Our data provide a strong basis for development of FXR-Gank-based therapy for treatment of patients with hepatoblastoma.

Accuracy of Cone Beam Computed Tomography Grayscale Density in Determining Bone Architecture in the Posterior Mandible: An In Vivo Study with Microcomputed Tomography Validation.

PURPOSE: The aim of this study was to analyze the reliability of cone beam computed tomography (CBCT) in assessing the grayscale density (GSD) of bone by comparing it with microcomputed tomography (µ-CT) data. MATERIALS AND METHODS: A total of 50 subjects with lost mandibular molars were included in the study. To assess the bone GSD, a previously fabricated template made of acrylic resin with a 2-mm-diameter metal rod was positioned, and CBCT was performed. The bone biopsies for µ-CT analysis were then obtained during implant surgery. The relationship between GSD assessed by CBCT and data from µ-CT analysis was studied using Spearman's rank correlation. RESULTS: A total of 38 biopsies were available for µ-CT analysis. Positive correlations were identified between GSD and bone volumetric fraction (BV/TV) (r = 0.835, P < .001), bone volume (BV) (r = 0.353, P = .030), trabecular spacing (Tb.Sp) (r = -0.535, P = .001), and mean total volume (TV) (r = 0.470, P = .003). There was a clear positive linear correlation between normal values of GSD (< 700) and BV (r = 0.545). CONCLUSION: This study demonstrated the correlation between GSD assessed by CBCT and bone density assessed by µ-CT in the posterior mandible. For areas of typical bone density, there seems to be a positive linear correlation between GSD assessed by CBCT and bone density assessed by µ-CT.

Influence of Posterior Mandibular Dimensions on Alveolar Bone Microarchitecture.

PURPOSE: The aim of this study was to investigate the influence of posterior mandibular dimensions (height and width at various levels) on alveolar bone microarchitecture using microcomputed tomography (micro-CT). MATERIALS AND METHODS: Partially edentulous subjects with one missing molar were included in the study. A bone core biopsy was performed at the site of planned implant surgery. For each patient, alveolar morphologic and architectural characteristics were analyzed using cone beam computed tomography (CBCT) and micro-CT imaging. Two parameters for height (apicocoronal residual height [RH] and residual ridge from inferior alveolar canal [RHN]) and three for buccolingual width (residual width at 5 mm [RW1], at 10 mm [RW2], and at 15 mm [RW3]) were determined using CBCT. Additionally, 10 parameters were obtained from micro-CT to determine microarchitecture. Pearson product-moment correlation coefficients were calculated to examine the correlation between the morphologic and microarchitectural variables. RESULTS: Significant positive correlations (P < .05) were found between RH and bone volumetric fraction (BV/TV) (rs = 0.34) and trabecular thickness (Tb.Th) (rs = 0.45). A significant negative correlation was found between RH and the bone-specific surface (BS/BV) (rs = -0.34). A strong significant negative correlation was found between trabecular spacing (Tb.Sp) and RW1 (rs = -0.42). None of the other variables reached statistical significance. CONCLUSION: Posterior mandibular dimensions may affect bony architectural characteristics.

Cystic Biliary Atresia and Choledochal Cysts Are Distinct Histopathologic Entities.

Cystic biliary atresia (CBA), a rare cystic expansion of atretic extrahepatic bile ducts in young infants, overlaps in age at presentation and imaging features with early choledochal cysts (CC). Treatment and prognosis differ; histologic differences are unsettled. We compared 10 patients with CBA, 1975 to 2015, to an age-similar cohort of 13 infants, and to older patients who had surgery for CC. Operative details, imaging, and clinical courses were correlated to pathologic specimens. Immunostains for smooth muscle actin and myosin heavy chain were used to evaluate cyst walls and atretic segments. CBA cysts typically lacked epithelium and inflammation; cyst walls had an inner, dense cicatricial layer associated with myofibroblastic (MF) hyperplasia that often delaminated producing a grossly visible inner cyst wall. Seven proximal biliary remnants in CBA featured circumferential peribiliary MF hyperplasia/fibrosis with little or no inflammation, similar to isolated BA. Extrahepatic atresia was usually both proximal and distal to the cyst. Features in 10/13 CC from infants and 8/8 CC in older patients had mostly preserved uninjured epithelium and no subepithelial cicatrix. Mural smooth muscle (absent in CBA) was present to some extent in CC at all ages. Unexpectedly, focal MF hyperplasia and laminar sclerosis was present in a few CC in infants, resembling CBA. CBA and infant CC are distinct histologic entities that occasionally overlap. CBA bile duct injury mimics non-CBA. Cystification is an aberrant manifestation of stromal proliferation in BA. The current management approach assuming CBA and CC in infants are 2 separate disease processes is supported but caution is advised.

The dendritic cell-T helper 17-macrophage axis controls cholangiocyte injury and disease progression in murine and human biliary atresia.

Biliary atresia (BA) is a fibroinflammatory obstruction of the extrahepatic biliary tree in neonates. While intrahepatic bile duct proliferation is universal at diagnosis, bile duct paucity develops later. We hypothesized that polarized T helper lymphocyte responses orchestrate progression of intrahepatic biliary injury in this disease. Interleukin 17A (IL-17A)-green fluorescent protein, cluster of differentiation 11c (CD11c)/diphtheria toxin receptor, and IL-17 receptor A-/- mice were used to examine T-lymphocyte polarization, inflammatory leukocyte recruitment, and biliary injury in rhesus rotavirus-induced BA. Multiparameter flow cytometry and automated image analysis of immunostaining were applied to liver tissue samples from infants with BA. In the mouse model, activated CD4+ lymphocytes started to emerge in the liver on day 8 after viral challenge, while innate immune responses were waning. Plasma IL-17A levels rose concomitantly with hepatic accumulation of T helper 17 lymphocytes and myeloid dendritic cells. Targeted depletion of CD11c+ dendritic cells diminished hepatic IL-17A production and ameliorated intrahepatic bile duct injury. Recombinant IL-17A induced expression of chemokine (C-C motif) ligand 2 in neonatal cholangiocytes in vitro, and blockade of the corresponding chemokine (C-C motif) receptor 2 reduced recruitment of inflammatory macrophages to the liver in vivo. Genetic disruption of IL-17A signaling was associated with down-regulation of hepatic Ccl2/Ccr2 messenger RNA expression, reduced infiltration of the liver with inflammatory Ly6Chi macrophages, and improved survival. In the liver of infants with BA, cholangiocytes were found to express IL-17 receptor A, and the prevalence of IL-17A+ cells was positively correlated with the degree of CD68+ macrophage infiltration at diagnosis. Hepatic CD4+ lymphocytes were chief producers of IL-17A in patients with progressive disease undergoing liver transplantation. CONCLUSION: These findings identify the dendritic cell-T helper 17-macrophage axis as a target for the development of strategies to block progression of intrahepatic bile duct injury in patients with BA. (Hepatology 2017;65:174-188).