Uterine mesothelial cysts mimicking ovarian cysts in a primipara patient with a history of Cesarean section: A case report and review of the literature.

OBJECTIVE: We describe a rare case of uterine mesothelial cysts mimicking ovarian cysts in a primipara patient with a history of Cesarean section. CASE REPORT: A 39-year-old female patient with history of Cesarean section presented with dysmenorrhea. Sonography revealed that a hypoechoic and anechoic multicystic complex, which was located on the right side of the pelvic cavity, had infiltrated the adjacent posterior wall of the uterus, and it was preoperatively misdiagnosed as ovarian cysts with suspected endometrioma. Laparoscopic surgery revealed multiple cystic lesions filled with clear yellow fluid on the posterior uterine wall instead of the adnexa. Laparoscopic uterine cystectomy was performed, and the patient's recovery was uneventful. Pathohistological and immunohistochemical examinations confirmed the diagnosis of uterine mesothelial cysts. CONCLUSION: Uterine mesothelial cysts should be considered in the differential diagnosis of pelvic lesions. Increasing the awareness of this rare disease can contribute to improved evaluation, decision-making, and disease management.

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.

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.

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.

Clinicopathologic features of de novo non-alcoholic steatohepatitis in the post-transplant setting.

BACKGROUND: Non-alcoholic steatohepatitis (NASH) has become an increasingly recognized problem in patients after orthotopic liver transplant. The aims of this study were to compare the clinicopathologic features of recurrent and de novo NASH. METHODS: From 1995 to 2016, we performed a retrospective review of patients with a histological diagnosis of non-alcoholic steatohepatitis made more than 6 months after liver transplant at University of California, San Francisco. The cases were categorized into de novo (n = 19) or recurrent steatohepatitis (n = 37). RESULTS: Hepatitis C virus (HCV) infection-related cirrhosis was the most common etiology of transplantation in de novo NASH (78% of cases, n = 29). There was no difference in glycogenosis or presence of grade 3 steatosis. More recurrent NASH biopsies had small ballooned hepatocytes (62.5% of cases) compared to de novo NASH (26.7%) (p = 0.03), and were less likely to show prominent portal inflammation (5% versus 40.5%, p = 0.0049). The diagnosis of recurrent NASH was made significantly sooner after transplantation than the diagnosis of de novo NASH (2.8 years versus 4.8 years, p = 0.02). CONCLUSIONS: Overall, our results support that recurrent NASH demonstrates distinct clinicopathologic features compared to de novo NASH arising in the post-transplant setting.

Decreased CD11c-positive dendritic cells in the tumor microenvironment predict double-hit/triple-hit genotype and survival in diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma and is a potentially curable disease. However, it is heterogenous, and the prognosis is poor if the tumor cells harbor fusions involving MYC and BCL2 or MYC and BCL6 (double-hit [DH] lymphoma), or fusions involving all three genes (triple-hit [TH] lymphoma). Fluorescence in situ hybridization is currently the gold standard for confirming the presence of DH/TH genotypes. However, the test is laborious and not readily available in some laboratories. Germinal center B (GCB) signatures and dual expression of MYC and BCL2 are commonly used as initial screening markers (traditional model) in clinical practice. Our study proposes immunohistochemical markers for more conveniently and accessibly screening DH/TH genotypes in DLBCL. We retrospectively reviewed the clinical and pathological parameters of patients with DLBCL. We assessed the proliferative index, apoptotic index, and tumor microenvironment (TME), with regard to T cells and CD11c(+) dendritic cells, in formalin-fixed paraffin-embedded tissue. We then generated a decision tree as a screening algorithm to predict DH/TH genotypes and employed decision curve analysis to demonstrate the superiority of this new model in prediction. We also assessed the prognostic significance of related parameters. Our study revealed that GCB subtypes, a Ki67 proliferative index higher than 70%, and BCL2 expression were significantly associated with DH/TH genotypes. Decreased CD11c(+) dendritic cells in the TME indicated additional risk. Our proposed screening algorithm outperformed a traditional model in screening for the DH/TH genotypes. In addition, decreased CD11c(+) dendritic cells in the DLBCL TME were an independent unfavorable prognosticator. In conclusion, we provide a convenient, well-performing model that predicts DH/TH genotypes in DLBCL. The prognostic significance of CD11c(+) dendritic cells in the TME might influence the classification and development of immunotherapy for DLBCL in the future.

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.

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.

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.

Lymphadenopathy Associated With Neutralizing Anti-interferon-gamma Autoantibodies Could Have Monoclonal T-cell Proliferation Indistinguishable From Malignant Lymphoma and Treatable by Antibiotics: A Clinicopathologic Study.

Early recognition of adult-onset immunodeficiency associated with neutralizing anti-interferon gamma autoantibodies (anti-IFNγ Abs) remains difficult, and misdiagnoses have been reported. Although febrile lymphadenopathy is among the most common initial manifestations of this disorder, no comprehensive clinicopathologic analysis of lymphadenopathy in patients with anti-IFNγ Abs has been reported. Here, we describe 26 lymph node biopsy specimens from 16 patients. All patients exhibited concurrent disseminated nontuberculous mycobacterial infections, and 31% received a tentative diagnosis of lymphoma at initial presentation. We found 3 distinct histomorphologic patterns: well-formed granuloma (46%), suppurative inflammation or loose histiocytic aggregates (31%), and lymphoproliferative disorder (LPD, 23%). The latter shared some of the features of malignant T-cell lymphoma, IgG4-related disease, and multicentric Castleman disease. Half of the specimens with LPD had monoclonal T cells, and 33.3% were indistinguishable from angioimmunoblastic T-cell lymphoma as per current diagnostic criteria. All lymphadenopathy with LPD features regressed with antibiotics without administration of cytotoxic chemotherapy or immunotherapy. The median follow-up time was 4.3 years. Our study highlights the substantial challenge of distinguishing between lymphoma and other benign lymphadenopathy in the setting of neutralizing anti-IFNγ Abs. Increased vigilance and multidisciplinary discussion among clinicians and pathologists are required to achieve the most appropriate diagnosis and management.

Lymphoepithelioma-like Intrahepatic Cholangiocarcinoma Is a Distinct Entity With Frequent pTERT/TP53 Mutations and Comprises 2 Subgroups Based on Epstein-Barr Virus Infection.

The molecular characteristics of lymphoepithelioma-like intrahepatic cholangiocarcinoma (LELCC) remain elusive. We examined 27 LELCC cases through next-generation sequencing using a panel of genes commonly mutated in primary liver cancers. Alterations in BAP1, ARID1A, ARID2, and PBRM1 were detected through immunohistochemistry. Fluorescence in situ hybridization was performed to analyze FGFR2 fusions and CCND1 amplification. LELCC is histologically classified as predominantly undifferentiated or glandular. Epstein-Barr virus-encoded small RNA (EBER) expression was found in 16 LELCCs. Approximately 50% of LELCCs expressed programmed death-ligand 1 strongly. Notably, recurrent pTERT and TP53 mutations were detected in 9 (38%) and 8 (33%) tumors, respectively. Only 2 LELCCs exhibited loss of expression for PBRM1. Alterations in genes typically involved in intrahepatic cholangiocarcinoma, including IDH1, IDH2, ARID1A, ARID2, and BAP1, and FGFR2 fusions, were not identified. The 2-step clustering analysis showed 2 distinct subgroups in LELCC, which were separated by EBER expression. A meta-analysis of all reported cases (n=85) has shown that EBER+ LELCC is strongly associated with the female sex, younger age, and exhibited predominantly glandular differentiation (P=0.001, 0.012, and <0.001, respectively). Patients with EBER- LELCC were more likely to have viral hepatitis and cirrhosis (P=0.003 and 0.005, respectively). Genetic analysis demonstrated that EBER- LELCC was significantly associated with pTERT and TP53 mutations (P=0.033 and 0.008, respectively). In conclusion, LELCC is genetically distinct from intrahepatic cholangiocarcinoma. EBER- LELCC may exhibit a different pathogenesis from EBER+ LELCC. High programmed death-ligand 1 expression in LELCC has implications for potential immunotherapeutic strategies.

Chemotherapy agents stimulate dendritic cells against human colon cancer cells through upregulation of the transporter associated with antigen processing.

Single immunotherapy fails to demonstrate efficacy in patients with microsatellite stable (MSS) metastatic colorectal cancer (mCRC). Research on immune reactions before and after systemic agents for mCRC is warranted. Our study examined cell line models to compare the expression of immune surface markers on colon cancer cells before and after chemotherapy agents. We also elucidated mechanisms underlying the effects of chemotherapy agents on immune surface markers. We used real-world clinical samples with NanoString analysis and the Perkin-Elmer Opal multiplex system. We established that chemotherapy agents, particularly 7-ethyl-10-hydroxycamptothecin (SN-38), the active metabolite of irinotecan, stimulated the expression of stimulatory MHC class I alleles through stimulation the pathway of transporters associated with antigen processing 1 and 2 (TAP1 and TAP2) in cell line models. Application of infected cell protein 47 (ICP-47), a specific inhibitor of the TAP1/TAP2, significantly inhibited expression of TAP1/TAP2 and also inhibited the expression of the downstream MHC class I. In the functional assay, SN-38 significantly promoted the phagocytosis of colon cancer cells by monocyte-derived dendritic cells (MoDCs). We confirmed that the expression of major histocompatibility complex (MHC) class I, significantly increased after first-line chemotherapy and targeted therapy in the samples of real-world patients with de novo mCRC. Our study provides new insights for novel 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.

An Integrative Morphomolecular Classification System of Gastric Carcinoma With Distinct Clinical Outcomes.

A robust morphomolecular classification system for gastric carcinoma is required. A 4-tier morphologic classification is proposed, including diffuse, intestinal, tubular, and lymphoid types. A tissue microarray for mismatch repair immunohistochemistry and Epstein-Barr virus (EBV) in situ hybridization were performed in 329 gastric carcinomas. DNA flow cytometry was used to detect aneuploidy in formalin-fixed paraffin-embedded samples. Lymphoid histology was the third most common histologic pattern at our institute and strongly associated with EBV infection and PMS2/MLH1-deficiency (both P<0.001). HER2 overexpression and SATB2 expression more frequently occurred in intestinal histology (both P<0.001). Loss of ARID1A expression was strikingly associated with lymphoid histology (P<0.001) and negative E-cadherin expression was correlated with diffuse histology (P=0.001). Programmed death-ligand 1 expression was most frequently present in lymphoid-type gastric carcinoma than other histologic subtypes and correlated with the molecular features of PMS2/MLH1-deficiency and EBV infection (all P<0.001). Aneuploidy was detected in 53% of gastric carcinomas and was highly correlated with intestinal type and the least with the lymphoid type (P<0.001). Notably, lymphoid-type gastric carcinoma showed the best outcome, whereas tubular type showed the worst survival rate (P<0.001). We integrated aneuploidy with morphologic patterns to propose a morphomolecular classification scheme, which served as a successful and independent prognostic factor in multivariate 5-year disease-free survival analysis (P<0.001). Overall, we describe an integrated morphomolecular classification system for gastric carcinomas to effectively predict patient outcomes. This system is cost-effective and reliable and can help select target therapeutics and facilitate clinical management.

Thrombotic Hemangioma With Organizing/Anastomosing Features: Expanding the Spectrum of GNA-mutated Hemangiomas With a Predilection for the Skin of the Lower Abdominal Regions.

In this study, we aimed to present the clinicopathologic and molecular features of a distinct group of hemangioma with GNA mutations that exhibited prominent thrombosis and organization changes with florid intravascular endothelial cell proliferation that we provisionally termed "thrombotic hemangioma with organizing/anastomosing features." Twenty-six cases were included. No sex predilection was seen (male:female=13:13). Patients' age ranged from 17 to 89 years (median: 51 y). All but 1 occurred in the skin whereas the remaining tumor involved the neck soft tissue. Remarkably, the majority (18) occurred in the lower abdominal/inguinal regions. Histologically, thrombotic hemangioma with organizing/anastomosing features were circumscribed tumors composed of variably sized and congested thin-walled vessels. The most striking features were prominent thrombosis and organization with florid intravascular endothelial cell proliferation. The proliferating endothelial cells exhibit a streaming pattern with focal anastomosing-like feature resembling anastomosing hemangioma. The stroma was sclerotic or hyalinized but could also be myxoid/edematous. Other features included vessels with nuclear hobnailing and perivascular hyalinization, cherry hemangioma-like component, cavernous-like or sinusoidal hemangioma-like areas, Masson hemangioma-like feature, and spindle cell fascicular pattern. Mitotic activity was usually low and nuclei were bland but 2 tumors exhibited moderate nuclear atypia and higher mitotic activity. Extramedullary hematopoiesis and hyaline globules were not identified. Genetically, by Sanger sequencing and MassARRAY analysis, mutually exclusive GNAQ, GNA11, and GNA14 exon 5 mutations were identified in 15, 5, and 2 tumors, respectively, with a combined mutation rate of 85% (22/26). In conclusion, we described a distinct group of hemangioma and expanded the clinicopathologic features of GNA-mutated hemangiomas.

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.

GNA11 joins GNAQ and GNA14 as a recurrently mutated gene in anastomosing hemangioma.

Anastomosing hemangioma (AH) is a distinct benign vascular tumor that may be histologically confused with an angiosarcoma. Recently, recurrent GNAQ and GNA14 mutations were identified in AH. GNA11, another paralogue of GNAQ and the one that shows the highest degree of homology to GNAQ, has not yet been found to be mutated in AH. In this study, we investigated the clinicopathological and molecular features of 26 AHs. By Sanger sequencing and MassARRAY analysis, mutually exclusive mutations in exon 5 of GNAQ, GNA11, and GNA14 were identified in 10, 5, and 5 tumors, respectively, of the 22 investigated tumors, with an overall mutation rate of 91%. No notable differences in the clinicopathological features were observed between GNAQ-, GNA11-, or GNA14-mutated tumors. Our results implicated GNA11 mutations, as well as previously known mutations of its paralogues GNAQ and GNA14, as essential drivers in the pathogenesis of AH.

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.