Hepatitis B reactivation: A possible cause of coronavirus disease 2019 vaccine induced hepatitis.

BACKGROUND AND AIMS: Coronavirus disease 2019 (COVID-19) vaccines were rapidly implemented globally and vaccine-associated immune-related hepatitis was recently reported. We aim to investigate its impact in regions endemic of chronic hepatitis B (CHB). METHODS: We retrospectively collected patients who developed hepatitis within 90 days after COVID-19 vaccination in Taiwan. The mechanisms of hepatitis included vaccine induced liver injury (VILI) and immune-related hepatitis, which are direct liver injuries defined as aspartate or alanine aminotransferase (AST or ALT) increased ≥ 5-fold upper limit of normal (ULN) and/or AST or ALT ≥ 3-fold of ULN with concurrent total bilirubin ≥ 2-fold of ULN. Indirect liver injury due to HBV reactivation was defined as HBsAg reverse seroconversion or significant rise in HBV DNA level. The demographics, clinical data, and course of hepatitis were compared statistically. RESULTS: Twenty-five patients were included with a median age of 54. The culprit vaccines were ChAdOx1 nCoV-19 (n = 9), mRNA-1273 (n = 12), and BNT162b2 (n = 4). The characteristics of hepatitis were comparable regardless of vaccine subtypes. The median onset of hepatitis was 25 days post vaccination, with a peak of 10-fold ALT-increase. The etiologies included HBV reactivation (n = 10), VILI (n = 10), and immune-related hepatitis (n = 5). HBV reactivation accounts for 90% of vaccine-induced hepatitis in patients of CHB (n = 10), and two patients died. Patients with initial AST levels >500 U/L increased 27-fold risks of liver injury greater than moderate severity compared with those without. CONCLUSION: COVID-19 vaccine induced hepatitis is a clinical significant complication, and HBV reactivation may account for a possible mechanism.

Novel prognostic implications of complement activation in the tumour microenvironment for de novo metastatic BRAF V600E mutant colorectal cancer.

BACKGROUND: Prognosis of metastatic BRAF V600E mutant colorectal cancer (CRC) is poor, and the prognostic implications of immune contextures in the tumour microenvironment (TME) for CRC remain elusive. METHODS: We collected the primary tumour specimens and clinicopathological characteristics of patients with de novo metastatic microsatellite-stable BRAF V600E mutant CRC from two medical centres. Gene expression analysis was performed using the nCounterⓇ PanCancer Immune Profiling Panel. The Cox proportional hazards regression model was used for analysing survival outcomes in association with immune gene expression and immune cells. Our complement score was defined on the basis of the average gene expression in the selected co-expression module. RESULTS: High expression of classical and regulatory complement genes was significantly associated with poor prognosis (N = 54). A high complement score (defined as a score above the median value) indicated significantly shorter survival. The overall survival (OS) impact of the high score remained significant in multivariate analyses. Additionally, our complement score was strongly correlated with C4d expression in immunohistochemical staining and tumour-associated macrophage (TAM) M2 signatures. CONCLUSIONS: Complement activation in the TME was significantly associated with poor OS and was correlated with TAM M2 in patients with de novo metastatic BRAF V600E mutant CRC.

Hepatic Sarcomatoid Carcinoma Is an Aggressive Hepatic Neoplasm Sharing Common Molecular Features With Its Conventional Carcinomatous Counterparts.

Hepatic sarcomatoid carcinoma is a rare hepatic tumor with an aggressive clinical behavior and dismal outcome. However, the molecular pathogenesis is incompletely defined. In this study, we analyzed 59 hepatic sarcomatoid carcinomas using targeted next-generation sequencing and immunohistochemistry. A panel of 14 genes commonly mutated in primary liver carcinomas was examined. PD-L1 and loss of expression for switch/sucrose nonfermenting complexes, including BAP1, ARID1A, ARID2, and PBRM1, were detected by immunohistochemistry. The 59 hepatic sarcomatoid carcinomas encompass various carcinomatous subtypes and tumors with complete sarcomatoid transformation. Mutations in TP53 and promoter of TERT (pTERT) were frequently identified in sarcomatoid hepatocellular carcinoma, sarcomatoid combined hepatocellular cholangiocarcinoma, and hepatic sarcomatoid carcinomas with complete sarcomatoid transformation but rarely in sarcomatoid cholangiocarcinoma. Alterations involving switch/sucrose nonfermenting complexes were uncommon in hepatic sarcomatoid carcinoma (n = 2). PD-L1 expressed in tumor-associated immune cells in 67% of the tumors and in tumor cells in 33% of the tumors. A multivariate survival analysis indicated that PD-L1 expression in immune cells served as an independent favorable predictive factor of patient survival (P = .036). In conclusion, hepatic sarcomatoid carcinoma displays molecular similarity with its conventional carcinomatous counterparts. This finding suggests persistent genetic characteristics during sarcomatous evolution. PD-L1 expression in immune cells is a favorable prognostic factor for patient outcomes and may be a potential biomarker for immunotherapeutic treatment.

Molecular features of primary hepatic undifferentiated carcinoma.

The clinicopathological and molecular characteristics of primary hepatic undifferentiated carcinoma are poorly defined. It is speculated that primary hepatic undifferentiated carcinoma develops in the setting of preceding primary hepatic carcinoma. We investigated 14 primary hepatic undifferentiated carcinomas through targeted next-generation sequencing and immunohistochemistry. A panel of genes commonly mutated in primary liver carcinomas were examined. We found a similar clinical context as primary hepatic carcinoma, including a high prevalence of chronic viral hepatitis (86%), cirrhosis (57%), and elevated alpha-fetoprotein (29%). Tumors had sheet-like and poorly cohesive growth patterns. Rhabdoid cytomorphology was observed in four samples. Notably, the most common genetic mutations in primary hepatic undifferentiated carcinoma were in the promoter of TERT (n = 8, 57%) and TP53 (n = 8, 57%), which are common in hepatocellular carcinoma. The mutation rate of TP53 was elevated compared with hepatocellular carcinoma. No other typical genetic features of intrahepatic cholangiocarcinoma were identified, such as an IDH1/IDH2 mutation, FGFR2 fusions, or aberrant BAP1 expression. Furthermore, novel switch/sucrose nonfermenting complex inactivation was found, including SMARCA4/SMARCA2 (n = 1) and PBRM1 deficiency (n = 2). The three tumors demonstrated poorly cohesive histology, including rhabdoid features. High PD-L1 expression (57%) was observed in a majority of the tumors. Primary hepatic undifferentiated carcinoma shares clinical and genetic features with hepatocellular carcinoma but harbors progressive molecular characteristics that may initiate tumor dedifferentation. High PD-L1 expression in primary hepatic undifferentiated carcinoma may be a useful biomarker for potential immunotherapeutic strategies.

Ramucirumab plus triplet chemotherapy as an alternative salvage treatment for patients with metastatic colorectal cancer.

BACKGROUND: Ramucirumab is indicated for salvage treatment after failure of first-line treatment for metastatic colorectal cancer (mCRC). However, the application of ramucirumab at later-line treatment in real-world practice has not received much discussion. METHODS: In this retrospective study, we enrolled 70 patients with mCRC who received ramucirumab plus chemotherapy at National Taiwan University Hospital between 2018 and 2019. RESULTS: Compared with those who received third- or later-line ramucirumab treatment, patients who received second-line ramucirumab treatment had significantly longer median time to treatment discontinuation (mTTD; 6.7 vs 3.6 months, P = .004) and median overall survival (mOS; not reached vs 7.6 months, P = .009). Multivariate analyses revealed that second-line ramucirumab and triplet chemotherapy backbone were the only independent predictive factors for long mTTD and mOS. Patients who received ramucirumab with triplet chemotherapy had a significantly longer mOS than did patients who received ramucirumab with doublet chemotherapy (not reached vs 5.6 months, P = .002). Among those receiving second-line ramucirumab treatment, combination with triplet chemotherapy led to a longer mTTD than did combination with doublet chemotherapy, but the difference was non-significant (not reached vs 4.4 months, P = .108). By contrast, in patients receiving fourth- or later-line ramucirumab, combination with triplet chemotherapy led to significantly longer mTTD than did combination with doublet chemotherapy (8.0 vs 2.9 months, P = .032). CONCLUSION: Ramucirumab plus triplet chemotherapy may be an alternative regimen in patients with mCRC, particularly as a later-line treatment modality.

Proteasome inhibitors restore the STAT1 pathway and enhance the expression of MHC class I on human colon cancer cells.

BACKGROUND: A new strategy, particularly a novel combination, for immunotherapy in microsatellite stable metastatic colorectal cancer (mCRC) treatment needs to be formulated. Studies on the interferon-γ (IFN-γ)/ Janus kinase (JAK)/ signal transducer and activator of transcription (STAT)1 pathway provide new directions in this regard. METHODS: Our study applies three colon cancer cell lines, including microsatellite stable (MSS) cell lines, which are SW480 and SW620, and microsatellite instability-high (MSI-H) cell line, which is DLD-1. We compared the expressions of immune surface markers on colon cancer cells in response to IFN-γ. We elucidated these mechanisms, which involved the upregulation of immune surface markers. Furthermore, we examined real-world clinical samples using the PerkinElmer Opal multiplex system and NanoString analysis. RESULTS: We established that the baseline expression of major histocompatibility complex (MHC) class I alleles and programmed death-ligand 1 (PD-L1) were generally low in cell line models. The immune surface markers were significantly increased after IFN-γ stimulation on SW480 but were notably unresponsive on the SW620 cell line. We discovered that STAT1 and phosphorylated STAT1 (pSTAT1) were downregulated in the SW620 cell line. We verified that the STAT1/pSTAT1 could be restored through the application of proteasome inhibitors, especially bortezomib. The expression of MHC class I as downstream signals of STAT1 was also up-regulated by proteasome inhibitors. The similar results were reproduced in DLD-1 cell line, which was also initially unresponsive to IFN-γ. In real-world samples of patients with mCRC, we found that higher STAT1 expression in tumor cells was strongly indicative of a highly immunogenic microenvironment, with significantly higher expression levels of MHC class I and PD-L1, not only on tumor cells but also on non-tumor cells. Furthermore, tumor infiltrating lymphocytes (TILs) were increased in the positive-STAT1 group. Through NanoString analysis, we confirmed that the mRNA expressions of IFN-γ, human leukocyte antigen (HLA)-A, HLA-E, and HLA-G were also significantly higher in the positive-STAT1 group than those in the negative-STAT1 group. CONCLUSION: Our study provides a novel rationale for the addition of bortezomib, a proteasome inhibitor, into new immunotherapy combinations.

Fatal acute-on-chronic liver failure in amiodarone-related steatohepatitis: a case report.

BACKGROUND: Amiodarone is an antiarrhythmic drug that has been recognized to induce hepatotoxicity. We report a case of acute-on-chronic liver failure (ACLF) in a patient who was receiving amiodarone for more than 2 years. The patient developed cirrhosis and suppurative microabscesses of the liver and died of progressive liver failure. CASE PRESENTATION: A 69-year-old woman with risk factors for nonalcoholic fatty liver disease (NAFLD) was treated with oral amiodarone at a daily dose of 400 mg for more than 2 years, until she developed epigastralgia and vomiting. Initial laboratory findings included leukocytosis and elevated liver enzymes. Images of abdominal computed tomography scan revealed diffusely increased hepatic attenuation density (in contrast to decreased density in NAFLD), hepatomegaly, periportal edema, and ascites. Liver biopsy targeting the hotspot identified through positron emission tomography confirmed the diagnosis of amiodarone-associated chronic steatohepatitis and superimposed microabscesses. The patient died of progressive ACLF despite intensive supportive care. CONCLUSION: Accumulation of amiodarone can result in chronic liver disease and pose an additional risk of ACLF following infection.

Hepatocellular adenoma in Taiwan: Distinct ensemble of male predominance, overweight/obesity, and inflammatory subtype.

BACKGROUND AND AIM: The clinicopathologic features of hepatocellular adenoma in Asian populations have been poorly defined. The study aimed to characterize this rare entity in a single institution in Taiwan. METHODS: In total, 45 hepatocellular adenomas from 1995 to 2018 were included and sent for pathologic review and molecular subtyping. RESULTS: The numbers of patients with hepatocellular adenoma has doubled in the recent decade. Surprisingly, men outnumbered women in our cohort (n = 26, 58% vs N = 19, 42%). A collection of clinical information revealed that overweight/obesity accounts for most of the associated conditions of hepatocellular adenoma. Only three women took oral contraceptives. There were 34 inflammatory (75%), three LFABP-negative (7%), four ß-catenin activated (9%), and four unclassified (9%) hepatocellular adenomas. Ten inflammatory hepatocellular adenomas demonstrated strong and homogeneous glutamine synthetase staining and were thus also ß-catenin activated. Notably, overweight and obesity were significantly associated with inflammatory hepatocellular adenoma than other subtypes (P = .029 and .056, respectively) and were strongly correlated with steatosis in background liver (P = .028 and.007, respectively). Malignant transformation (four borderline tumors and two hepatocellular carcinomas) was identified in six adenomas (two women and four men). All six hepatocellular adenomas with malignancy were ß-catenin activated; ß-catenin activation could serve as a biomarker for malignant progression. CONCLUSIONS: The clinicopathologic features of hepatocellular adenoma in Taiwan are distinct from those reported in Western countries. Rare oral contraceptive usage and an emerging epidemic of overweight/obesity in Taiwan provides new insights into the pathogenesis of hepatocellular adenoma.

High frequency of GNA14, GNAQ, and GNA11 mutations in cherry hemangioma: a histopathological and molecular study of 85 cases indicating GNA14 as the most commonly mutated gene in vascular neoplasms.

Cherry hemangioma is the most common hemangioma in adult life. Neoplastic and non-neoplastic theories had both been proposed for its pathogenesis, but its nature is still poorly understood. We noted a significant subset of anastomosing hemangiomas and congenital hemangiomas harbored a population of small capillaries surrounded by a perivascular hyaline layer, reminiscent of the vessels seen in cherry hemangioma. Both anastomosing hemangioma and congenital hemangioma harbor recurrent mutations in exon 5 of GNAQ and its paralogues. In this study, we analyzed 68 cherry hemangiomas and 17 cherry hemangioma-like hemangiomas exhibiting additional non-classical features including markedly dilated, cavernous vessels, and/or a deep component extending to the deep dermis. By Sanger sequencing, GNAQ, GNA11, and GNA14 exon 5 mutations were identified in 12, 4, and 32 cherry hemangiomas, respectively, and 5, 3, and 3 cherry hemangioma-like hemangiomas, respectively. MassARRAY analysis detected mutations (including exon 2 GNAQG48V mutations) in additional 8 cherry hemangiomas and 3 cherry hemangioma-like hemangiomas. Overall, the cherry hemangiomas and cherry hemangioma-like hemangiomas had equal GNA mutation rates (82%), and GNA14 and GNAQ mutations were present in approximately half of cherry hemangiomas and cherry hemangioma-like hemangiomas, respectively. All mutations were mutually exclusive. KRASG12V mutation was also detected in one cherry hemangioma-like hemangioma without GNA mutations. In summary, our study demonstrated recurrent GNA14/GNAQ/GNA11 mutations were present in the majority of this very common hemangioma and established its neoplastic nature. Our results also expanded the morphological spectrum of GNA-mutated hemangiomas to include tumors composed of cavernous-like vessels and indicated GNA14 was the most commonly mutated gene in vascular tumors.

Targeted next-generation sequencing identifies distinct clinicopathologic and molecular entities of intraductal papillary neoplasms of the bile duct.

Intraductal papillary neoplasm of the bile duct (IPNB) is a mass-forming neoplasm in the bile duct considered to be the biliary counterpart of pancreatic intraductal papillary mucinous neoplasm (IPMN). By its cell lineage, IPNB can be classified into gastric, intestinal, pancreatobiliary, and oncocytic types. Recently, a group of Japanese and Korean pathologists proposed that IPNB be classified into two types, with type 1, being the histological counterpart of IPMN and type 2, having a more complex histological architecture. We used targeted next-generation sequencing to study the molecular change of 37 IPNBs and identified frequent mutations of KRAS (49%), GNAS (32%), RNF43 (24%), APC (24%), TP53 (24%), and CTNNB1 (11%) in IPNBs. Intestinal-type IPNB was associated with KRAS, GNAS, and RNF43 mutations. Japan-Korea consensus type 1 was associated with KRAS and GNAS mutations. All four IPNBs with CTNNB1 mutations were of pancreatobiliary type and located in the extrahepatic bile duct. A hierarchical analysis identified three distinct groups within IPNB: group 1 was Japan-Korea consensus type 1 tumors with macroscopic mucin, old age, and frequent KRAS, GNAS, and RNF43 mutations. Group 2 was Japan-Korea consensus type 2 with intestinal differentiation and frequent KRAS mutation but rare GNAS mutation, MUC2 expression, and macroscopic mucin. Group 3 was characterized by CTNNB1 mutation, extrahepatic location, lack of expression of intestinal markers, Japan-Korea consensus type 2, and lack of mutations in KRAS, APC, RNF43, and GNAS. Our results indicated that IPNB is a heterogeneous disease and that the activation of Ras-mitogen-activated protein kinase (MAPK), Wnt/ß-catenin, and G-protein-coupled receptor (GPCR)-cAMP signaling is the main oncogenic mechanism of IPNB.

CpG Island Methylator Phenotype May Predict Poor Overall Survival of Patients with Stage IV Colorectal Cancer.

OBJECTIVE: We aimed to study the prognostic role of CpG island methylator phenotype (CIMP) in patients with different stages of colorectal cancer (CRC). MATERIAL AND METHODS: We analyzed CIMP in stage I-IV CRC specimens from patients who were diagnosed between 2005 and 2013. CIMP status was determined using a 5-gene MethyLight-based assay. The clinicopathologic characteristics were reviewed and the overall survival (OS) was compared between patients with CIMP-high CRC and those with CIMP-low/negative CRC. RESULTS: Among 450 CRC specimens with successfully determined CIMP statuses, 74 (16.4%) were CIMP-high CRC. Although there was no difference in OS between patients with CIMP-high and CIMP-low/negative CRC across all stages (p = 0.4526), intriguingly, patients with stage IV CIMP-high CRC had significantly worse OS than those with stage IV CIMP-low/negative CRC (p = 0.0047). In a multivariate analysis, CIMP status remained an independent prognostic factor for overall mortality (HR = 5.60, 95% CI: 2.12-14.79, p = 0.0005) in metastatic CRC after adjusting for clinicopathologic variables and anti-cancer therapies. CONCLUSION: Our results revealed that the presence of CIMP independently predicts poor OS in patients with stage IV CRC.

Diagnosis and risk stratification of Barrett's dysplasia by flow cytometric DNA analysis of paraffin-embedded tissue.

OBJECTIVE: The diagnosis of dysplasia in Barrett's oesophagus (BO) can be challenging, and reliable ancillary techniques are not available. This study examines if DNA content abnormality detected by flow cytometry can serve as a diagnostic marker of dysplasia and facilitate risk stratification of low-grade dysplasia (LGD) and indefinite for dysplasia (IND) patients using formalin-fixed paraffin-embedded (FFPE) BO samples with varying degrees of dysplasia. DESIGN: DNA flow cytometry was performed on 80 FFPE BO samples with high-grade dysplasia (HGD), 38 LGD, 21 IND and 14 negative for dysplasia (ND). Three to four 60-micron thick sections were cut from each tissue block, and the area of interest was manually dissected. RESULTS: DNA content abnormality was identified in 76 HGD (95%), 8 LGD (21.1%), 2 IND (9.5%) and 0 ND samples. As a diagnostic marker of HGD, the estimated sensitivity and specificity of DNA content abnormality were 95% and 85%, respectively. For patients with DNA content abnormality detected at baseline LGD or IND, the univariate HRs for subsequent detection of HGD or oesophageal adenocarcinoma (OAC) were 7.0 and 20.0, respectively (p =<0.001). CONCLUSIONS: This study demonstrates the promise of DNA flow cytometry using FFPE tissue in the diagnosis and risk stratification of dysplasia in BO. The presence of DNA content abnormality correlates with increasing levels of dysplasia, as 95% of HGD samples showed DNA content abnormality. DNA flow cytometry also identifies a subset of patients with LGD and IND who are at higher risk for subsequent detection of HGD or OAC.

Association of Aneuploidy and Flat Dysplasia With Development of High-Grade Dysplasia or Colorectal Cancer in Patients With Inflammatory Bowel Disease.

There is controversy over how to best manage patients with inflammatory bowel disease and flat low-grade dysplasia (fLGD) in the colon. We performed a retrospective analysis of formalin-fixed paraffin-embedded colon tissues with fLGD from 37 patients undergoing surveillance colonoscopy for inflammatory bowel disease from 1990 to 2015 at the University of California at San Francisco Medical Center, to determine whether detection of aneuploidy is associated with later development of high-grade dysplasia (HGD) or colorectal cancer. Medical data were collected from the patients for a mean follow-up time of 37 months. Using flow cytometry analysis of paraffin-embedded colon tissue, we detected aneuploidy in 15 of 37 samples with fLGD (40.5%). By comparison, aneuploidy was detected in 14 of 15 samples with flat HGD (93.3%) and 2 of 45 samples that were negative for dysplasia (4.4%). The univariate hazard ratio for subsequent detection of HGD or colorectal cancer in patients with fLGD and aneuploidy was 5.3 (95% CI, 1.542-24.121) within a mean follow-up time of 37 months. The presence of aneuploidy therefore identifies patients with fLGD in colon tissue who have an increased risk for HGD or colorectal cancer and may provide supportive evidence to a morphologic impression or suspicion of flat HGD.

Aggressive non-alcoholic steatohepatitis following rapid weight loss and/or malnutrition.

While non-alcoholic steatohepatitis is a slowly progressive disease, patients may rarely present in acute liver failure. We describe six patients who developed severe hepatic dysfunction following rapid weight loss or malnutrition. Rapid weight loss (18 to 91 kg) occurred after Roux-en-Y gastric bypass in four patients and starvation-like dieting or hypoalbuminemia was noted in two patients. Four patients either died or received an urgent liver transplant. Pathologic findings were characterized by advanced alcoholic steatohepatitis-like features, including extensive/circumferential centrizonal pericellular fibrosis, central scar with perivenular sclerosis/veno-occlusion with superimposed hepatocellular dropout, abundant/prominent hepatocellular balloons, and numerous Mallory-Denk bodies, but there was no history of excess alcohol consumption. This study characterizes clinicopathologic features of aggressive non-alcoholic steatohepatitis following rapid weight loss or malnutrition, which should be included in the differential diagnosis with alcohol when a patient is considered for liver transplantation. The mechanism of liver injury in aggressive steatohepatitis is unknown, but rapid fat mobilization in obese patients may potentially cause oxidative stress to the liver and further study is needed to determine if there is a genetic predisposition to this form of injury and if antioxidants may protect the liver during rapid weight loss/malnutrition.

RNF43 mutation frequently occurs with GNAS mutation and mucin hypersecretion in intraductal papillary neoplasms of the bile duct.

AIMS: RNF43 is a tumour suppressor gene that suppresses the Wnt-ß-catenin signalling pathway. We investigated the role of RNF43 in intraductal papillary neoplasm of the bile duct (IPNB). METHODS AND RESULTS: We conducted mutation analysis of RNF43 in 50 IPNBs, and identified six (12%) RNF43 mutations. RNF43 mutation was more frequent in the intestinal subtype of IPNB (17%) than in the gastric/pancreatobiliary subtype (5%). There was a strong association of RNF43 mutation with GNAS (P = 0.007) mutation, and a borderline correlation with KRAS (P = 0.074) mutation. The presence of macroscopic mucin hypersecretion was closely related to RNF43 (P = 0.024) and GNAS (P < 0.001) mutations. A two-step clustering analysis algorithm successfully categorized IPNBs into two subgroups by using the clinicopathological and molecular features of IPNBs. One subgroup of IPNB represented the 'biliary counterpart of intraductal papillary mucinous neoplasm of the pancreas' (biliary-IPMN), and showed unique features reminiscent of IPMN, such as macroscopic and microscopic mucin hypersecretion, an intestinal cell lineage, GNAS mutation, and RNF43 mutation. Biliary-IPMNs were significantly associated with high expression of cytokeratin (CK) 20, mucin 2 (MUC2), and CDX2, as shown by immunostaining (P = 0.032, P = 0.001, and P = 0.026, respectively), and had a borderline association with low expression of CK7 (P = 0.063). With the use of this splitting algorithm, RNF43 mutations were identified in 36% of the biliary-IPMNs. CONCLUSIONS: The identification of RNF43 mutations in a distinct subset of IPNBs revealed a new molecular role in the pathogenesis of IPNB, and provided a potential application for cancer therapeutics by the use of Wnt pathway inhibitors.

Frequent PIK3CA activating mutations in nipple adenomas.

AIMS: Nipple adenoma (NA) is a rare benign epithelial tumour occurring in the nipple. Histologically, it exhibits variable and often mixed adenosis-like and usual ductal hyperplasia-like growth patterns. Morphologically, it is similar to other benign proliferative breast lesions occurring in the breast parenchyma, which have been shown to harbour activating mutations in PIK3CA, AKT1 or, less frequently, in RAS in more than 50% of cases. In this study, we aimed to analyse the mutation status of PIK3CA, AKT1, RAS and BRAF in NAs and correlated the mutation status with the histological features. METHODS AND RESULTS: Mutation analysis of PIK3CA, AKT1, RAS and BRAF was performed in 24 NAs by Sanger sequencing. Our results showed that activating PIK3CA mutations were identified in eight of the 15 NAs (53%) with a predominantly adenosis-like pattern and four of the nine NAs (44%) with a predominantly usual ductal hyperplasia-like pattern. One tumour with a PIK3CA H1047R mutation also had a KRAS Q61H mutation. Two tumours with an adenosis-like pattern had BRAF V600E mutations. Overall, half of the NAs (12 of 24, 50%) in our series had PIK3CA mutations and 58% (14 of 24) had PIK3CA, RAS or BRAF mutations. CONCLUSIONS: Our data indicate that, similar to other benign proliferative lesions occurring in the breast parenchyma, activating PIK3CA mutations are very common in NAs, and KRAS mutation may occur concurrently with PIK3CA mutation. In addition, as BRAF mutation has not been identified in benign proliferative lesions in previous studies, BRAF-mutated NAs appear to have distinct pathogenesis.

Complementary roles of ß-catenin and glutamine synthetase immunostaining in diagnosis of chemotherapy-treated and untreated hepatoblastoma.

BACKGROUND/PURPOSE: This study aimed to evaluate the expression of ß-catenin and its downstream target glutamine synthetase (GS) in hepatoblastoma (HB), and to evaluate the use of these two markers for diagnosing HB. METHODS: Eighteen untreated HBs and 22 HBs resected after neoadjuvant chemotherapy were analyzed using ß-catenin and GS immunostaining. RESULTS: We detected nuclear ß-catenin immunostaining in nearly all untreated HBs, including in fetal and embryonal epithelial components and in mesenchymal elements. We also observed diffuse GS expression in the epithelial component; however, it was frequently absent in embryonal and mesenchymal areas. In HBs resected after neoadjuvant chemotherapy, we recognized four histological patterns: fetal, hepatocellular-carcinoma-like, clear-cell, and normal-liver-like. All these patterns displayed diffuse GS expression. Fetal pattern showed diffuse nuclear ß-catenin immunostaining. Nuclear ß-catenin immunostaining was weak in the hepatocellular-carcinoma-like and clear-cell patterns. In normal-liver-like area, ß-catenin expression was only located in the cell membrane. CONCLUSION: The results suggest that nuclear ß-catenin expression and diffuse GS immunostaining are the hallmarks of HB. Although epithelial and mesenchymal components of HB display nuclear ß-catenin staining, this expression is attenuated following chemotherapy-induced cell maturation. GS immunostaining is especially useful for the assessment of section margins after neoadjuvant chemotherapy.

Traditional serrated adenoma with BRAF mutation is associated with synchronous/metachronous BRAF-mutated serrated lesions.

AIMS: To determine whether traditional serrated adenoma (TSA) results in an increased risk of developing subsequent serrated polyps or colorectal cancer (CRC). METHODS AND RESULTS: We recruited 111 patients with an index TSA, and analysed the pathological and molecular features of their synchronous/metachronous serrated lesions. Fifty hyperplastic polyps, 14 sessile serrated adenomas, an additional 27 TSAs and 17 CRCs were identified from 46 patients. Twenty-seven percent of TSAs showed a precursor serrated polyp in the periphery and were strongly correlated with BRAF mutation (P < 0.001). Serrated polyps occurred more commonly in patients with BRAF-mutated index TSAs than in patients with KRAS-mutated index TSAs. BRAF-mutated index TSAs were strongly associated with a right-sided location and BRAF mutation of synchronous/metachronous serrated polyps (P = 0.013 and P = 0.005, respectively). The 17 CRCs occurred more frequently in women, and were characterized by a high BRAF mutation rate (59%), a positive CpG island methylator phenotype (59%), and stable or low levels of microsatellite instability (77%). CONCLUSIONS: BRAF-mutated TSA is distinct from KRAS-mutated TSA in predisposing to the acquisition of subsequent serrated neoplasia. This indicates the presence of an intestinal field defect in the tumour microenvironment that results in tumour initiation and malignant progression.

Alternative lengthening of telomeres and loss of ATRX are frequent events in pleomorphic and dedifferentiated liposarcomas.

Telomerase activation and alternative lengthening of telomeres are two major mechanisms of telomere length maintenance. Soft tissue sarcomas appear to use the alternative lengthening of telomeres more frequently. Loss of α-thalassemia/mental retardation syndrome X-linked (ATRX) or death domain-associated protein 6 (DAXX) expression has been implicated in the pathogenesis of alternative telomere lengthening in pancreatic endocrine neoplasm and glioma. The mechanism leading to the alternative lengthening of telomeres in liposarcoma remains unknown. Whereas alternative telomere lengthening was determined to be an indicator of poor prognosis in liposarcomas as a whole, its prognostic power has not been verified in any subtype of liposarcoma. In this study, we characterized the status of alternative telomere lengthening and expression of ATRX and DAXX in 111 liposarcomas (28 well-differentiated, 52 dedifferentiated, 20 myxoid or round cell, and 11 pleomorphic liposarcomas) by telomere fluorescence in situ hybridization and immunohistochemistry, respectively. Alternative lengthening of telomere was observed in 0% (0/16) of well-differentiated, 30% (14/46) of dedifferentiated, 5% (1/19) of myxoid or round cell, and 80% (8/10) of pleomorphic liposarcomas. Eighteen (16%) and one (1%) tumors were negative for ATRX and DAXX immunostaining, respectively. Remarkably, all cases with loss of either ATRX or DAXX expression had alternative lengthening of telomeres, and 83% (19/23) of tumors that had alternative lengthening of telomeres showed loss of either protein. The correlation between loss of either ATRX or DAXX and alternative telomere lengthening was 100% in dedifferentiated liposarcoma. The presence of alternative telomere lengthening in dedifferentiated liposarcoma suggested poor overall survival (hazard ratio=1.954, P=0.077) and was the most significant indicator of short progression-free survival (hazard ratio=3.119, P=0.003). In conclusion, we found that ATRX loss was the most likely mechanism of alternative telomere lengthening in liposarcoma and alternative telomere lengthening was a prognostic factor of poor outcome in dedifferentiated liposarcoma.