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The implementation of AI assisted cancer detection systems in clinical environments has faced numerous hurdles, mainly because of the restricted explainability of their elemental mechanisms, even though such detection systems have proven to be highly effective. Medical practitioners are skeptical about adopting AI assisted diagnoses as due to the latter's inability to be transparent about decision making processes. In this respect, explainable artificial intelligence (XAI) has emerged to provide explanations for model predictions, thereby overcoming the computational black box problem associated with AI systems. In this particular research, the focal point has been the exploration of the Shapley additive explanations (SHAP) and local interpretable model-agnostic explanations (LIME) approaches which enable model prediction explanations. This study used an ensemble model consisting of three convolutional neural networks(CNN): InceptionV3, InceptionResNetV2 and VGG16, which was based on averaging techniques and by combining their respective predictions. These models were trained on the Kvasir dataset, which consists of pathological findings related to gastrointestinal cancer. An accuracy of 96.89% and F1-scores of 96.877% were attained by our ensemble model. Following the training of the ensemble model, we employed SHAP and LIME to analyze images from the three classes, aiming to provide explanations regarding the deterministic features influencing the model's predictions. The results obtained from this analysis demonstrated a positive and encouraging advancement in the exploration of XAI approaches, specifically in the context of gastrointestinal cancer detection within the healthcare domain., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Auzine et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

In the last two decades, the increasing availability of technologies for molecular analyses has allowed an insight in the genomic alterations of neuroendocrine neoplasms (NEN) of the gastrointestinal tract and pancreas. This knowledge has confirmed, supported, and informed the pathological classification of NEN, clarifying the differences between neuroendocrine carcinomas (NEC) and neuroendocrine tumors (NET) and helping to define the G3 NET category. At the same time, the identification genomic alterations, in terms of gene mutation, structural abnormalities, and epigenetic changes differentially involved in the pathogenesis of NEC and NET has identified potential molecular targets for precision therapy. This review critically recapitulates the available molecular features of digestive NEC and NET, highlighting their correlates with pathological aspects and clinical characteristics of these neoplasms and revising their role as predictive biomarkers for targeted therapy. In this context, the feasibility and applicability of a molecular classification of gastrointestinal and pancreatic NEN will be explored., (© 2024. The Author(s).)

Background: Gastrointestinal cancers account for approximately 20% of all cancer diagnoses and are responsible for 22.5% of cancer deaths worldwide. Artificial intelligence-based diagnostic support systems, in particular convolutional neural network (CNN)-based image analysis tools, have shown great potential in medical computer vision. In this systematic review, we summarise recent studies reporting CNN-based approaches for digital biomarkers for characterization and prognostication of gastrointestinal cancer pathology., Methods: Pubmed and Medline were screened for peer-reviewed papers dealing with CNN-based gastrointestinal cancer analyses from histological slides, published between 2015 and 2020.Seven hundred and ninety titles and abstracts were screened, and 58 full-text articles were assessed for eligibility., Results: Sixteen publications fulfilled our inclusion criteria dealing with tumor or precursor lesion characterization or prognostic and predictive biomarkers: 14 studies on colorectal or rectal cancer, three studies on gastric cancer and none on esophageal cancer. These studies were categorised according to their end-points: polyp characterization, tumor characterization and patient outcome. Regarding the translation into clinical practice, we identified several studies demonstrating generalization of the classifier with external tests and comparisons with pathologists, but none presenting clinical implementation., Conclusions: Results of recent studies on CNN-based image analysis in gastrointestinal cancer pathology are promising, but studies were conducted in observational and retrospective settings. Large-scale trials are needed to assess performance and predict clinical usefulness. Furthermore, large-scale trials are required for approval of CNN-based prediction models as medical devices., Competing Interests: Conflict of interest statement The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: TJB would like to disclose that he is the owner of Smart Health Heidelberg GmbH (Handschuhsheimer Landstr. 9/1, 69,120 Heidelberg, Germany, https://smarthealth.de) which developed the teledermatology services AppDoc (https://online-hautarzt.net) and Intimarzt (https://Intimarzt.de), outside the scope of the submitted work. JNK reports a consulting role at Owkin, France. All remaining authors have declared no conflicts of interest., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Asian Americans (AAs) are heterogeneous, and aggregation of diverse AA populations in national reporting may mask high-risk groups. Gastrointestinal (GI) cancers constitute one-third of global cancer mortality, and an improved understanding of GI cancer mortality by disaggregated AA subgroups may inform future primary and secondary prevention strategies. Using national mortality records from the United States from 2003 to 2017, we report age-standardized mortality rates, standardized mortality ratios and annual percent change trends from GI cancers (esophageal, gastric, colorectal, liver and pancreatic) for the six largest AA subgroups (Asian Indians, Chinese, Filipinos, Japanese, Koreans and Vietnamese). Non-Hispanic Whites (NHWs) are used as the reference population. We found that mortality from GI cancers demonstrated nearly 3-fold difference between the highest (Koreans, 61 per 100 000 person-years) and lowest (Asian Indians, 21 per 100 000 person-years) subgroups. The distribution of GI cancer mortality demonstrates high variability between subgroups, with Korean Americans demonstrating high mortality from gastric cancer (16 per 100 000), and Vietnamese Americans demonstrating high mortality from liver cancer (19 per 100 000). Divergent temporal trends emerged, such as increasing liver cancer burden in Vietnamese Americans, which exacerbated existing mortality differences. There exist striking differences in the mortality burden of GI cancers by disaggregated AA subgroups. These data highlight the need for disaggregated data reporting, and the importance of race-specific and personalized strategies of screening and prevention., (© 2021 UICC.)

Background and Aims: Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the digestive tract with malignant potential. The current risk classification standard is unable to accurately evaluate the invasiveness and clinical outcomes of GISTs. Ki-67 labelling index (LI) may be an effective indicator in assessing tumour invasiveness and prognosis, however, its exact value in GISTs is still uncertain. The aims of our study were to evaluate the correlation of the Ki-67 LI and clinicopathological features of GISTs and to assess the potential value of the Ki-67 LI in GISTs classification and prognosis., Methods: The clinical, pathological and prognostic data were collected and analysed to identify the independent influential factors of GISTs risk stratification and the predictors of GISTs prognosis., Results: The Ki-67 LI was significantly associated with the clinicopathological features of tumour progression (P<0.05). It was an independent influential factor of GISTs risk classification (odds ratio: 1.322; 95% confidence interval: 1.031-1.696) (P=0.028), and the area under the curve (AUC) value of the Ki-67 LI on the discrimination ability of GISTs risk stratification was 0.906 (P<0.001). The optimal cutoff value of the Ki-67 LI was 6% (sensitivity of 87.5% and specificity of 76.2%), and patients with Ki-67 LI≥6% exhibited significantly poorer progression-free survival (PFS) than those with Ki-67 LI<6% (P<0.001). The AUC value of the Ki-67 LI for predicting PFS in postoperative patients was 0.813 (P=0.03)., Conclusions: The Ki-67 LI has appreciated value to predict the risk grade and prognosis of GISTs. Patients with Ki-67 LI≥6% are prone to recurrence and metastasis after operation and may need a close follow-up., (Copyright © 2020 Elsevier España, S.L.U. All rights reserved.)

Neuroendocrine neoplasms (NENs) of the gastrointestinal tract (GIT) comprise neuroendocrine tumours (NETs) and neuroendocrine carcinomas (NECs). During the last decade the classification and grading of GIT NENs has undergone significant changes, culminating in the World Health Organisation (WHO) 2019 classification. These changes, some of which are attributable to an only partially successful attempt to achieve uniform nomenclature among different organs, include: slight changes to the cut-off used for the Ki-67 proliferative index to distinguish grade 1 from grade 2 NETs; an emphasis on the distinction between grade 3 NETs (low-grade NETs with a high proliferative rate) and NECs which, by definition, are all high grade; classification of tumours with mixed non-neuroendocrine and neuroendocrine differentiation as MiNENs; and replacement of the term 'goblet cell carcinoid' with 'goblet cell adenocarcinoma'. While some of these changes seem minor, even semantic, each was made for very specific reasons which reflect an improved understanding of neuroendocrine neoplasia. The changes have definite implications for pathologists in clinical practice, not all of which may be readily apparent. This review is an attempt to explain the background behind each of the recent changes to the classification of neuroendocrine neoplasms of the gastrointestinal tract and summarise their impact on surgical pathologists - including a guide on how to approach certain recurrent difficulties encountered with the WHO 2019 system in routine clinical practice., (© 2020 John Wiley & Sons Ltd.)

Background: In 2014, the World Health Organization (WHO) released a classification system introducing neuroendocrine neoplasms (NENs) of the female reproductive tract, excluding the ovaries. This study aimed to evaluate whether retrospective adaption of the gastroenteropancreatic (GEP)-NEN classification is feasible for ovarian NENs (O-NENs) and correlates with prognosis., Methods: Sixty-eight patients diagnosed with carcinoid, small cell carcinoma (pulmonary type), paraganglioma, non-small/large cell neuroendocrine carcinoma (NEC), mixed NEC, or undifferentiated carcinomas at 20 institutions in Japan were included in this retrospective cross-sectional study. We identified O-NENs through central pathological review using a common slide set, followed by reclassification according to WHO 2010 guidelines for GEP-NENs. A proportional hazards model was used to assess the association of prognostic factors (age, stage, performance status, histology, and residual disease) with overall survival (OS) and progression-free survival (PFS)., Results: Of the 68 enrolled patients, 48 were eligible for analysis. All carcinoids (n = 32) were reclassified as NET G1/G2, whereas 14 of 16 carcinomas were reclassified as NEC/mixed adeno-NEC (MANEC) (Fisher's exact test; p < 0.01). The OS/PFS was 49.0/42.5 months and 6.5/3.9 months for NET G1/G2 and NEC/MANEC, respectively. Histology revealed that NEC/MANEC was associated with increased risk of death (HR = 48.0; 95% CI, 3.93-586; p < 0.01) and disease progression (HR = 51.6; 95% CI, 5.54-480; p < 0.01)., Conclusion: Retrospective adaption of GEP-NEN classification to O-NENs is feasible and correlates well with the prognosis of O-NENs. This classification could be introduced for ovarian tumors., (© 2020 S. Karger AG, Basel.)

Background: Patients suffering from gastrointestinal cancer comprise a large group receiving home hospice care in China, however, little is known about the prediction of their survival time. This study aimed to develop a gastrointestinal cancer-specific non-lab nomogram predicting survival time in home-based hospice., Methods: We retrospectively studied the patients with gastrointestinal cancer from a home-based hospice between 2008 and 2018. General baseline characteristics, disease-related characteristics, and related assessment scale scores were collected from the case records. The data were randomly split into a training set (75%) for developing a predictive nomogram and a testing set (25%) for validation. A non-lab nomogram predicting the 30-day and 60-day survival probability was created using the least absolute shrinkage and selection operator (LASSO) Cox regression. We evaluated the performance of our predictive model by means of the area under receiver operating characteristic curve (AUC) and calibration curve., Results: A total of 1618 patients were included and divided into two sets: 1214 patients (110 censored) as training dataset and 404 patients (33 censored) as testing dataset. The median survival time for overall included patients was 35 days (IQR, 17-66). The 5 most significant prognostic variables were identified to construct the nomogram among all 28 initial variables, including Karnofsky Performance Status (KPS), abdominal distention, edema, quality of life (QOL), and duration of pain. In training dataset validation, the AUC at 30 days and 60 days were 0.723 (95% CI, 0.694-0.753) and 0.733 (95% CI, 0.702-0.763), respectively. Similarly, the AUC value was 0.724 (0.673-0.774) at 30 days and 0.725 (0.672-0.778) at 60 days in the testing dataset validation. Further, the calibration curves revealed good agreement between the nomogram predictions and actual observations in both the training and testing dataset., Conclusion: This non-lab nomogram may be a useful clinical tool. It needs prospective multicenter validation as well as testing with Chinese clinicians in charge of hospice patients with gastrointestinal cancer to assess acceptability and usability.

Background: Decisions about multimodality treatment for upper gastrointestinal malignancies are largely predicted on clinical staging information. However, hospital-level accuracy of clinical staging is currently unknown., Methods: A national cohort study of patients with adenocarcinoma of the esophagus, stomach, or pancreas in the NCDB (2006-2015) who were treated with upfront resection. Hospital-level staging accuracy (ascertained by comparing clinical stage to pathologic stage) was calculated. Within hospital correlation of staging accuracy across disease sites was evaluated using risk and reliability adjustment., Results: Overall, 1246 hospitals were evaluated. Median hospital T-staging accuracy was 77.5%, 73.7%, and 60.8% for esophageal, gastric, and pancreatic cancer, respectively. Median hospital N-staging accuracy was 80.2%, 72.9%, and 61.8%, respectively. For T-stage, over-staging was most frequently observed in esophageal patients (11.2%) while under-staging was most frequent in pancreatic patients (36.1%). For N-stage, over-staging was infrequent for all three, while under-staging was most common in pancreatic patients (37.4%). Correlation across disease sites was weak for both T- (best observed, r = .34) and N-stages (r = .30). When high volume hospitals were evaluated, correlation improved but accuracy rates were similar., Conclusions: Despite the importance of clinical staging in multimodality treatment planning, hospitals inaccurately stage 20-40% of patients, with low correlation across disease sites., (© 2020 Wiley Periodicals LLC.)

Myeloid-derived suppressor cells (MDSCs) are immunosuppressive cells that are increased in patients with numerous malignancies including viral-derived hepatocellular carcinoma (HCC). Here, we report an elevation of MDSCs in the peripheral blood of patients with other hepatobiliary malignancies including non-viral HCC, neuroendocrine tumors (NET), and colorectal carcinoma with liver metastases (CRLM), but not cholangiocarcinoma (CCA). The investigation of myeloid cell infiltration in HCC, NET and intrahepatic CCA tumors further established that the frequency of antigen-presenting cells was limited compared to benign lesions, suggesting that primary and metastatic hepatobiliary cancers have distinct peripheral and tumoral myeloid signatures. Bioinformatics analysis of The Cancer Genome Atlas dataset demonstrated that a high MDSC score in HCC patients is associated with poor disease outcome. Given our observation that MDSCs are increased in non-CCA malignant liver cancers, these cells may represent suitable targets for effective immunotherapy approaches.

This review reflects a collaboration between the American Registry of Pathology (the publisher of the Armed Forces Institute of Pathology Fascicles) and Annals of Diagnostic Pathology. It is part of a series of expert recommendations on topics encountered in daily practice. The authors, three pathologists with expertise in gastrointestinal tract pathology and immunohistochemistry, met on 30 July 2019 tasked with developing expert recommendations for evaluating poorly differentiated and undifferentiated malignant neoplasms encountered on mucosal biopsies of the gastrointestinal tract. We focused on esophageal, gastric, small intestinal, colorectal, and anal (i.e., tubal gut) samples. When faced with diagnostic uncertainty on the initial H&E, it is best to begin by trying to assign the broad tumor class with screening markers such as pankeratin, S100 protein or SOX10, and CD20 or CD45. Once a broad tumor class is established, more specific differentiation markers can be pursued (e.g., lineage-restricted transcription factors for adenocarcinoma; p40 for squamous cell carcinoma; chromogranin A and synaptophysin or INSM1 for neuroendocrine neoplasms). Every small biopsy containing tumor should be considered a potential molecular pathology sample; cutting extra unstained slides with this testing in mind is strongly encouraged., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Purpose: Gastrointestinal stromal tumors (GISTs) are typically solid neoplasms with small cystic change detected occasionally but in rare instances may present predominantly as cystic lesions. The histopathologic features and prognoses of cystic GISTs (cGISTs) are poorly understood., Methods: We herein reviewed 20 cGISTs resected or consulted in our institution from January 1, 2003 to December 31, 2014., Results: Of the 20 patients included, the mean age was 61 years and the male-to-female ratio was 9:11. The original locations were the stomach (n = 10, 50%), the small intestine (n = 9, 45%) and the omentum (n = 1, 5%). Indistinct diagnosis or misdiagnosis was established in 15 cases based only on preoperative radiology. Grossly, the cystic component made up the bulk of masses and was filled by dark bloody fluid and necrotic debris in 18 cases. Microscopically, cyst wall was composed of neoplastic spindle (n = 14, 70%)/epithelioid cells (n = 6, 30%) and collagenous fiber, with necrotic debris and granulation tissue lining on the inner surface. cGISTs resembled their solid counterparts in terms of morphology and immunohistology but demonstrated fewer malignant parameters. c-kit or PDGFRα mutations were detected in eleven cases with the remaining being wild type for these two mutations. Although classified as intermediate or high (3 and 17, respectively) risk of recurrence according to modified National Institute of Health criterion, most patients with cGISTs experienced long-term recurrence-free survival without adjuvant imatinib., Conclusions: Cystic GISTs is a relatively indolent subset of GISTs with favorable prognoses and adjuvant imatinib should be a prudent consideration.

Introduction: Lymph node retrieval and quantification is an important element in staging upper gastrointestinal cancers. Our department introduced fat clearance for oesophagectomy and gastrectomy specimens in 2014. This study assessed the impact of this change on lymph node yield and upstaging., Methods: We reviewed histopathology data for upper gastrointestinal resection specimens. Patient demographics, clinical, macroscopic and microscopic data were compared with a historical cohort who did not undergo fat clearance., Results: Of 158 patients, 133 resection specimens received fat clearance resulting in a significantly higher lymph node yield than the historical cohort (22 vs 13 lymph nodes, p<0.0001). Fat clearance found additional positive nodes in 24.1% of patients and increased the number of cases achieving a minimum node yield of 15. Nodes found by fat clearance caused upstaging in 15% of the cohort., Discussion: Fat clearance increases node yield in upper gastrointestinal resection specimens and may cause nodal upstaging., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Although various risk classification systems for GISTs have been proposed, the optimum one remains uncertain. In the present study, we compared the prognostic stratification of different risk classification systems for GIST patients., Methods: We reviewed those patients who were pathologically diagnosed with GISTs in the SEER database between 2009 and 2014. All patients were classified into different risk groups according to the NIH criteria, AFIP criteria and AJCC staging system, respectively. The prognostic differences between different risk groups were compared and clinicopathologic features were analyzed., Results: The prognosis of small intestinal GISTs was not significantly different from that of gastric GISTs. For gastric GIST patients, there was no significant prognostic difference between very low risk and low risk group according to the NIH and AFIP criteria. However, the prognostic stratification for two groups could be improved by the AJCC staging system. For small intestinal GIST patients, the prognostic difference between low risk and intermediate risk group was not stratified properly by the NIH and AFIP criteria. However, the prognostic difference between two groups could reach statistical significance according to the AJCC staging system. Unlike gastric GISTs, tumor size was not identified as an independent factor influencing the prognosis of small intestinal GISTs., Conclusions: The AJCC staging system could provide a better prognostic stratification for GIST patients compared with the NIH and AFIP criteria, regardless of gastric or small intestinal tumor. However, primary tumor location and tumor size may be reconsidered and revised in the risk classification system.

We analyzed 921 adenocarcinomas of the esophagus, stomach, colon, and rectum to examine shared and distinguishing molecular characteristics of gastrointestinal tract adenocarcinomas (GIACs). Hypermutated tumors were distinct regardless of cancer type and comprised those enriched for insertions/deletions, representing microsatellite instability cases with epigenetic silencing of MLH1 in the context of CpG island methylator phenotype, plus tumors with elevated single-nucleotide variants associated with mutations in POLE. Tumors with chromosomal instability were diverse, with gastroesophageal adenocarcinomas harboring fragmented genomes associated with genomic doubling and distinct mutational signatures. We identified a group of tumors in the colon and rectum lacking hypermutation and aneuploidy termed genome stable and enriched in DNA hypermethylation and mutations in KRAS, SOX9, and PCBP1., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Aim: The aim of this study is to investigate the clinicopathological characteristics, as well as explore the prognostic accuracy of the proposed new classification in gastrointestinal NENs (GI-NENs) patients., Methods: Patients diagnosed with GI-NENs were retrospectively indentified from existing databases of the pathological institute at our institution from January 2009 to November 2015., Results: We identified 414 patients with GI-NENs, 250 cases were diagnosed as neuroendocrine tumor G1 (NET G1), 25 as neuroendocrine tumor G2 (NET G2), 53 as neuroendocrine tumor G3 (NET G3), 55 as neuroendocrine carcinoma G3 (NEC G3), and 31 as mixed adenoneuroendocrine carcinoma (MANEC); the overall survival (OS) rate at three years were 94.9%, 91.7%, 74.3%, 62.7% and 38.1%, respectively. The difference in progression-free survival (PFS) duration among the patients with NET G1, NET G2, NET G3, NEC G3, and MANEC was statistically significant (P < 0.001). However, the PFS of NEC G3 and MANEC was low and similar (P = 0.090). In multivariate analysis of patients with GI-NENs, surgical margin, comorbidity, proposed new classification and tumor location were useful predictors of OS (P < 0.05)., Conclusion: Our findings suggest that the proposed new classification can accurately reflect the clinical outcome, together with surgical margin, comorbidity, and tumor location may be meaningful prognostic factors for the OS of GI-NENs., (© 2017 John Wiley & Sons Australia, Ltd.)

Aims: This multi-institutional study and a re-evaluation of the TCGA cohort explores the morphological spectrum, genetics and outcome of GI (gastrointestinal) hepatoid tumours, tumours expressing alpha-fetoprotein (AFP) and fetal-type (FT) GI adenocarcinomas., Methods: 44 tumours with evidence of hepatocellular differentiation were evaluated for morphology as well as by immunohistochemistry for AFP, HepPar1, glypican-3 and arginase-1 and by in situ hybridisation for albumin. Three categories were defined: type I (hepatoid: morphological evidence of hepatocellular differentiation), type II (FT GI adenocarcinoma: tubular profiles and subnuclear vacuolisation, resembling fetal intestine) and type III: positive for at least two hepatocyte-specific markers but lacking morphological evidence of hepatocellular differentiation. GI adenocarcinomas in the TCGA cohort were also evaluated (n=829)., Results: 18 cases were classified as type I, 19 as FT GI adenocarcinomas and 7 as type III (resembling conventional gastrointestinal carcinomas). Serum AFP was elevated in 92% of cases. 93% of tumours were positive for glypican-3, 90% for albumin and 89% for AFP. Arginase-1 was restricted to 35% of type 1 tumours. TCGA gastric tumours with elevated AFP expression showed morphological features of FT GI adenocarcinoma (70%) and were exclusively MSI stable. TCGA gastric adenocarcinomas with high AFP expression showed inferior survival on univariate and multivariate analysis., Conclusions: FT GI adenocarcinomas show a distinctive morphological and immunohistochemical profile. Gastric adenocarcinomas with elevated expression of AFP morphologically resemble FT GI adenocarcinomas, demonstrate aggressive behaviour, independent of grade and stage, and a distinct genetic profile., Competing Interests: Competing interests: The work was partially funded by a sponsored research agreement between the authors’ institution and Affymetrix, California, USA., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background: Tumors arising from neuroendocrine cells are defined as epithelial neoplasms with predominantly neuroendocrine differentiation. They comprise a distinct group of tumors with a characteristic histological structure and functional properties that develop at various sites, particularly the gastrointestinal system (67%) and lungs (25%). Although such tumors are usually slow-growing and indolent, almost all have malignant potential and most can produce active hormones. Clinical signs vary, and many are dependent on the site at which the tumor develops. Although these tumors were identified more than 130 years, their classification remains unclear., Purpose: This review provides a comprehensive overview of the human neuroendocrine system and its neoplasms, from their discovery to current terminology and classifications. In addition, the clinical symptomatology and macroscopic/microscopic features of tumors arising from endocrine cells of the gastrointestinal tract are described, with an emphasis on their classification, diagnostic criteria for their grading and TNM (tumor, node, metastasis) staging, and how these tumors differ according to their localization in the gastrointestinal tract., Conclusion: Tumors arising from neuroendocrine cells are rare and can cause typical symptoms of carcinoid syndrome. However, most of these tumors are asymptomatic, which, together with their typical small size and localization in the gut, makes them difficult to access endoscopically and often leads to diagnosis at an advanced stage. To successfully diagnose and treat tumors arising from neuroendocrine cells, they should be assessed using a differential diagnostic procedure and be histopathologically classified, graded, and staged according to specified criteria and the latest classifications and guidelines. Although the terms "carcinoid", "neuroendocrine tumor", and "neuroendocrine carcinoma" are often used synonymously in the literature and by professionals, more precise terminology is required for nomenclature and classification. Key words: gastrointestinal neuroendocrine neoplasms - neuroendocrine tumors - neuroendocrine carcinomas - classification - NET - NEC The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 21. 3. 2018 Accepted: 16. 4. 2018.

Soft tissue tumours are relatively rare, but are diagnostically challenging as they comprise a large spectrum of diagnostic entities. Substantial advances have been made in recent years in identifying the underlying recurrent chromosomal and genomic alterations in a significant subset of soft tissue tumours, and this continues to enrich our understanding of the biological mechanisms of tumour development and progression. Ongoing validation and integration of these findings into existing pathological-diagnostic algorithms has led to re- or subclassification of diagnostic categories and will continue to shape a more nuanced (and hopefully clinically relevant) tumour classification system in the future. This review provides a selective overview of recent diagnostic or conceptual advances in the categories of peripheral nerve sheath tumours, vascular and adipocytic tumours, round cell and myogenic sarcomas, and gastrointestinal stromal tumours, as well as their underlying molecular mechanisms, some of which have been translated successfully into useful immunohistochemical stains. A thorough and critical validation of newly identified diagnostic markers-acknowledging the fact that some genetic alterations may not necessarily be tumour-specific-and ongoing correlation with clinical and prognostic implications will be necessary in this regard., (Copyright © 2017 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.)

Objective: To investigate the clinical characteristics, pathological classification and prognostic factors of gastrointestinal neuroendocrine neoplasms (GI-NENs)., Methods: Clinicopathological data of 119 GI-NENs patients at Shanghai Renji Hospital from November 2007 to December 2016 were analyzed retrospectively. According to the classification and grading criteria of the WHO Neuroendocrine Tumor 2010 edition, patients were classified pathologically to realize the malignant degree of tumors. The overall survival rate was calculated by Kaplan-Meier curve, the prognostic risk factors were analyzed by Cox regression model, and the factors including the platelet/lymphocyte ratio (PLR) and neutrophil/lymphocyte ratio (NLR) were included in the analysis in addition to the routine clinicopathological factors., Results: Of 119 patients with GI-NENs, there were 83 cases (69.7%) of male and 36 cases (30.3%) of female. The age of patients ranged from 24 to 86 (median 61) years. Tumor locations included the stomach(n=70, 58.8%), duodenum(n=10, 8.4%), small intestine(n=2, 1.7%), appendix(n=3, 2.5%), colon(n=12, 10.1%), and rectum(n=22, 18.5%). The tumor diameter was 0.6 to 20 cm, the mean diameter was 5.4 cm, and the median diameter was 4 cm. There were 25 cases of G1 neuroendocrine tumor (NET), 7 cases of G2 NET and 87 cases of G3 neuroendocrine carcinoma (NEC). Among the 119 patients, 113 cases (95%) had complete follow-up, and the median follow-up was 75 (1 to 112) months. The 5-years overall survival rate was 58.4%. The survival rate of G1 NET, G2 NET and G3 NEC were 100%, 71.4%, 44.4%, and the difference was statistically significant (P=0.000). Univariate analysis showed that age ≥61 years (P=0.000), tumor located in the stomach, duodenum and colon (P=0.041), tumor size ≥4 cm (P=0.002), pathology classification of G3 NEC (P=0.000), late TNM staging (P=0.000) and blood PLR ≥133 (P=0.017) were associated with lower 5-year survival rate, but blood NLR level was not(P=0.263). Multivariate analysis showed that the patient age (HR=3.036, 95%CI: 1.548 to 5.956, P=0.001), the pathology classification(HR = 1.852, 95%CI:1.099 to 3.122, P=0.021), lymph node metastasis (HR=2.635, 95%CI:1.198 to 5.797, P=0.016) and distant metastasis (HR=2.685, 95%CI:1.383 to 5.214, P=0.004) were independent risk factors affecting the prognosis of patients, but the blood PLR level was not (HR=1.735, 95%CI: 0.947 to 3.176, P=0.074)., Conclusions: The malignant degree of GI-NEN is quite high, and the prognosis of patients is relatively poor. The age, pathological type and TNM staging are closely related to the prognosis of patients. Preoperative blood PLR may play a role in the prediction of prognosis, but preoperative blood NLR is not related with the prognosis of patients.

Background: Neuroendocrine tumors (NETs) of the gastrointestinal tract are a heterogeneous group of tumors which have different malignant potential and evolution. The World Health Organization (WHO) has set up a new classification of gastrointestinal NETs in 2010. However, it does not evaluate the risk of malignancy for each tumor., Aim: To evaluate the prognostic impact of the WHO classification in 2010 by reclassifying the tumor according to new recommendations and to identify histoprognostic factors to better predict changes., Methods: This is a descriptive retrospective study of 36 cases of gastrointestinal NETs, collected at the pathological anatomy department in Rabta hospital, over a period of 11 years from 2003 to 2013., Results: Our series included 11 NETs of Appendix, nine of the pancreas, seven of the small bowel, four of the stomach, three of the rectum, one of the colon and one of the esophagus. The mean age of patients across all sites, was 50.3 years old and the sex ratio was 0,44. The tumors were classified according to the 2010 WHO classification. They were divided into: G1 in 27 cases (75%); G2 in three cases (8.3%); G3 small cell carcinoma in two cases (5.6%); G3 large cell carcinoma in one case (2.8%) and mixed adeno-neuroendocrine carcinoma in three cases (8.3%)., Conclusion: Our study has shown limits of the latest 2010 WHO classification of NETs. The prognosis of these tumors could be better predicted by the evaluation of other histoprognostic factors and by the improvement of criteria defining histological degrees including tumor size.

Malignancies of the gastrointestinal tract are among the most common human cancers. The distinct tissues of origin give rise to a diverse set of diseases, such as colorectal cancer, pancreatic carcinoma and gastric cancers, with each associating with specific clinical features. Genomic and transcriptomic analyses have further defined the heterogeneity that occurs within these cancers by identifying so-called molecular subtypes. These subtypes are characterized by specific genetic aberrations and expression signatures that suggest important biological differences. Although at first sight this subdivision of organ-specific cancers might increase the complexity of classification, closer analysis suggests that the subtypes detected in the various malignancies are recurring. For example, nearly all gastrointestinal cancers appear to present with subtypes that are either characterized by a mesenchymal gene expression signatures, extensive immune infiltration or metabolic dysregulation. Additionally, in each of the gastrointestinal malignancies, a 'canonical' subtype is recognized that retains characteristic features of the epithelial tissue of origin. These common themes can enhance our collective understanding of these malignancies, and could perhaps be therapeutically exploited. In this Review, the identification of subtypes in the various gastrointestinal cancer types are discussed along with how they could be incorporated into clinical practice.

Background: Gastrointestinal cancers are characterized by a male predominance, suggesting a role of sex hormones. We hypothesized that digitalis medication, due to its estrogenic properties, decreases the risk of male-predominated gastrointestinal cancers., Results: Long -term digitalis use (≥2 years) was followed by decreased risk for several gastrointestinal cancers, but associations were statistically significant only for liver cancer (hazard ratio [HR]=0.40, 95% confidence interval (CI) 0.16-0.98). Short-term (<1 year) use was associated with an increased risk of esophageal squamous cell carcinoma (HR=1.79, 95% CI 1.01-3.17), colorectal cancer (HR=1.72, 95% CI 1.57-1.89), gallbladder cancer (HR=1.93, 95% CI 1.04-3.59), and pancreatic cancer (HR=1.33, 95% CI 1.00-1.76), but no such increase was found among long-term users., Methods: We performed a nationwide population-based cohort study in Sweden. Participants included 156,385 individuals using digitalis and a reference group of 551,933 users of organic nitrates between 2005 and 2013, who were identified in the Swedish Prescribed Drug Register. New diagnoses of gastrointestinal cancers were identified from the Swedish Cancer Register. Hazard ratios of gastrointestinal cancers in digitalis users compared to users of organic nitrates were calculated from Cox proportional hazards regression with adjustment for sex, age, municipality of residence and comorbidity., Conclusions: This study suggests a decreased risk of male-predominated gastrointestinal cancers, particularly of liver cancer, in long-term users of digitalis. Short-term use may be associated with an increased risk of esophageal squamous cell carcinoma, colorectal cancer, gallbladder cancer, and pancreatic cancer.The use of digitalis as preventive or therapeutic agents remains to be fully evaluated.

Purpose: Current staging criteria for gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs), while useful, have limitations. In this study, we used a population-based registry to evaluate the prognostic utility of the current staging systems and assess whether evidence-based modifications can improve survival predictions., Methods: We identified patients with confirmed GEP-NENs from the Surveillance, Epidemiology and End Results registry. We assigned tumour-node-metastasis status according to American Joint Committee on Cancer and European Neuroendocrine Tumor Society criteria. We derived a revised staging classification using Kaplan-Meier methods and Cox regression to assess disease-specific survival and compared the accuracy of potential models based on the Akaike Information Criterion (AIC) and Harrell's C-index. The revised classification was validated in an independent set., Results: We identified 10,268 patients with GEP-NENs. We found that multiple stages, as determined by current criteria, misclassified patients' prognosis. In particular, stage IIIB (T1-4N1) had overlapping survival with stage IIIA (T4N0). A revised system which reclassifies N1 disease into different stages based on T status (T1-2N1, T3N1 and T4N1) had an improved AIC (difference = 38) and C-index (0.86) compared to current staging. These revisions improved predictions in patients with both low and high-grade tumours from all primary sites. Results also were confirmed across all primary sites in the validation set., Conclusion: Current staging guidelines misclassify the prognosis of N1 patients. Our results suggest that a revised system could lead to better prognostication for GEP-NEN patients. Further validation followed by implementation of these revisions may improve treatment selection and design of clinical trials., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The purpose of the present review is to analyze the cytohistological and immunohistochemical characteristics of spindle-shaped mesenchymal gastrointestinal neoplams (MGNs), a group of unusual neoplastic conditions with different biological behavior. These tumors exhibit clinical pictures strictly related to the site of origin and dimensions, even if they appear generally with an intramural localization. This latter point may suggest an useful application of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), mainly followed by the cell-block procedure (CBP) in the differential diagnostic approach. First of all, we discuss the most common entity of MGNs represented by gastrointestinal stromal tumors (GISTs), analyzing the morphologic characteristics and stressing the strength of immunohistochemical algorithm for diagnostic purposes. Successively, we have reported the less common group of spindle-shaped MGNs comprehensive of those arising elsewhere the soft tissues, such as leiomyomas, leiomyosarcomas, schwannomas, inflammatory myofibroblastic tumor and intra-abdominal desmoid fibromatosis. Finally, very uncommon spindle-shaped MGNs, like clear cell, follicular dendritic cell, undifferentiated pleomorphic and radiation-induced sarcomas as well as spindle cell dedifferentiated liposarcomas, have been briefly mentioned.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Despite this, GISTS comprise about 2% in the structure of digestive tract cancers. They are usually localized in the stomach; however, they can be found in the small intestine and more rarely in the colon and esophagus. Although approximately 70% of the GISTs consist predominantly of spindle cells; the epithelioid cell tumors represent 20% of cases; there are also mixed variants. This variability in the morphological structure of GISTs complicates their diagnosis.

Additional primary malignancies in patients with gastrointestinal stromal tumor (GIST) is not only common but of growing interest in the scientific literature. This association is of great importance in terms of clinical challenge, diagnosis and therapy as well as for the prognosis impact it implies. In the published series there is a tendency to group these patients to determine the specific and distinguishable characteristics of GIST associated with other malignancies. On the other hand, there is no general consensus or unified classification. This classification would be of great interest, as it would unify criteria, agree groups to compare different series and demonstrate whether the aetiology underlying both tumours and the GIST's own characteristics really vary according to the type in question. We undertook a medical literature review and proposed a new classification for patients with GIST associated with other tumours., (Copyright © 2016 Elsevier España, S.L.U. All rights reserved.)

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) constitute a heterogeneous group of tumours associated with variable clinical presentations, growth rates, and prognoses. To improve the management of GEP-NENs, the WHO developed a classification system that enables tumours to be graded based on markers of cell proliferation in biopsy specimens. Indeed, histopathology has been a mainstay in the diagnosis of GEP-NENs, and the WHO grading system facilitates therapeutic decision-making; however, considerable intratumoural heterogeneity, predominantly comprising regional variations in proliferation rates, complicates the evaluation of tumour biology. The use of molecular imaging modalities to delineate the most-aggressive cell populations is becoming more widespread. In addition, molecular profiling is increasingly undertaken in the clinical setting, and genomic studies have revealed a number of chromosomal alterations in GEP-NENs, although the 'drivers' of neoplastic development have not been identified. Thus, our molecular understanding of GEP-NENs remains insufficient to inform on patient prognosis or selection for treatments, and the WHO classification continues to form the basis for management of this disease. Nevertheless, our increasing understanding of the molecular genetics and biology of GEP-NENs has begun to expose flaws in the WHO classification. We describe the current understanding of the molecular characteristics of GEP-NENs, and discuss how advances in molecular profiling measurements, including assays of circulating mRNAs, are likely to influence the management of these tumours.

The current WHO classification of neuroendocrine tumors (NET) differentiates between typical carcinoids (low grade NET), atypical carcinoids (intermediate grade NET) and small cell and large cell carcinomas (high grade NET) according to the prognosis. Neuroendocrine neoplasms (NEN) of the gastrointestinal tract and the pancreas are graded in an identical way. Together with the TNM system this enables a preoperative estimation of the prognosis in biopsies and fine needle aspirates. Well-differentiated tumors are graded into G1 tumors by the number of mitoses, <2 per 10 high-power fields (HPF) and the Ki-67 (index <3 %) and G2 tumors (2-20 mitoses/10 HPF, Ki-67 3-20 %). Discrepancies between the number of mitoses and the Ki-67 index are not uncommon and in these cases the higher value of the two should be applied. The more differentiated tumors of the G3 type have to be differentiated from undifferentiated carcinomas of the small cell type and large cell type with a much poorer prognosis. Prognosis relevant grading of thyroid cancers is achieved by special subtyping so that the G1-G3 system is not applicable. The rare cancers of the parathyroid gland and of the pituitary gland are not graded. Adrenal tumors also have no grading system. The prognosis is dependent on the Ki-67 index and with some reservations on the established scoring systems.

Background: The lack of uniform criteria for coding of gastroenteropancreatic neuroendocrine neoplasia (GEP-NEN) has hampered previous epidemiological studies. The epidemiology of GEP-NEN was investigated in this study using currently available criteria., Methods: All patients diagnosed with GEP-NEN between January 2003 and December 2013 in a well defined Norwegian population of approximately 350 000 people were included. Age- and sex-adjusted incidence rates were calculated. The current 2010 World Health Organization criteria, European Neuroendocrine Tumour Society classification and International Union Against Cancer (UICC) classification were used., Results: A total of 204 patients (114 male, 55.9 per cent) were identified. The median age at diagnosis was 61 (range 10-94) years. The annual overall crude incidence was 5.83 per 100,000 inhabitants, with an increasing trend (P = 0.033). The most frequent location was small intestine (60 patients, 29.4 per cent) followed by appendix (48 patients, 23.5 per cent) and pancreas (33 patients, 16.2 per cent). Grade 1 tumours were more common in gastrointestinal (100 patients, 58.5 per cent) than in pancreatic (9 patients, 27 per cent) NEN. According to the UICC classification, 77 patients (37.7 per cent) had stage I, 17 patients (8.3 per cent) stage II, 37 patients (18.1 per cent) stage III and 70 patients (34.3 per cent) had stage IV disease. No patient with stage I disease had grade 3 tumours; advanced tumour grade increased with stage., Conclusion: A high crude incidence of GEP-NEN, at 5.83 per 100,000 inhabitants, was noted together with a significant increasing trend over time., (© 2015 The Authors. BJS published by John Wiley & Sons Ltd on behalf of BJS Society Ltd.)

Background: Gastro-entero-pancreatic neuroendocrine neoplasms (GEP-NEN) are relatively rare tumors, not equally distributed in the gastrointestinal system. In 2010, a revised version of the WHO classification of GEP-NENs was published. This study reports for the first time the distribution and characteristics of GEP-NENs in a Lebanese population., Materials and Methods: This descriptive retrospective study concerns all the digestive neuroendocrine tumors with their characteristics diagnosed in Hotel Dieu de France in Beirut, Lebanon from 2001 to 2012, all the pathology reports being reanalyzed according to the latest WHO 2010 classification. The characteristics and features of GEP-NEN analyzed in this study were age, gender, grade and site., Results: A total of 89 GEP-NENs were diagnosed, representing 28.2% of all neuroendocrine tumors. The mean age of GEP-NEN patients was 58.7 years and the M/F sex ratio was 1.2. The primary localization was as follows: 21.3%(19) pancreatic, 18% (16) gastric, 15.7% (14) duodenal, 11.2% (10) appendix, 10.1% (9) intestinal, 10.1% (9) colorectal (7.9% colonic and 2.2% rectal), 5.6% (4) hepatic, 2.2% (2) ampulla, 1.1% (1) esophageal and 7.9%(5) NOS digestive (metastatic with unknown primary). Of the 89 patients with GEP-NEN, 56.2% (50) were diagnosed as grade I, 11.2% (10) as grade II, 20.2% (18) as grade III and 12.4% (11) were considered as mixed adeno-neuroendocrine carcinomas (MANEC)., Conclusions: This study, one of the rare examples based on the 2010 WHO classification of neuroendocrine tumors in the literature, indicates that in the Lebanese population, all duodenal and appendicular tumors are G1 and the majority of MANEC tumors are gastric and pancreatic tumors. Moreover, more duodenal tumors and fewer rectal tumors were encountered in our study compared to European reports.

Objective: To assess the prognostic value in Chinese patients of two new systems, the World Health Organization (WHO)-2010 and the American Joint Committee on Cancer and the Union for International Cancer Control (AJCC/UICC) systems, for the classification of gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN)., Methods: One hundred and three patients with GEP-NEN treated at the First Affiliated Hospital of Nanjing Medical University from January 2003 to December 2011 were included in the study. All patients were diagnosed pathologically and had complete follow-up data. Univariate and multivariate analyses of their clinicopathological characteristics were performed., Results: The 5-year survival rates were 95%, 74%, 24% and 15% based on the AJCC/UICC stages I to IV, and 92%, 62% and 29% according to WHO-2010 grades 1 to 3, respectively, in patients with GEP-NEN. A higher mortality was observed in patients with AJCC/UICC stage III and IV tumors compared with those at stage I-II, and patients with stage II compared with those with stage I, whereas there was no difference in survival between stage IV and III patients. Based on the WHO-2010 grading classification, patients with grade 3 tumors had the lowest survival rate than those with grade 1 and 2 tumors, followed by patients with grade 2 tumors., Conclusion: The WHO-2010 and AJCC/UICC staging systems can effectively evaluate the prognosis of patients with GEP-NEN, although the latter might not accurately discriminate the prognosis of patients with local metastasis from those having distant metastasis., (© 2015 Chinese Medical Association Shanghai Branch, Chinese Society of Gastroenterology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.)

Rapid growth in knowledge of cell and molecular biology led to the increased usage of molecular techniques in anatomical pathology. This is also due to the advances achieved in the techniques introduced in the last few years which are less laborious as compared to the techniques used at the beginning of the "molecular era". The initial assays were also very expensive and were not performed except for selected centers. Moreover, the clinicians were not sure how to make use of the accumulating molecular information. That situation has also changed and molecular techniques are being performed in a wide variety of medical settings which also has a reflection on the endocrine system pathology among other organ systems. This review will provide an update of genetic changes observed in different endocrine system pathologies and their diagnostic, therapeutic and prognostic values.

The gastroenteropancreatic (GEP) system is the site of origin of about two thirds of all neuroendocrine neoplasms (NENs) of the human body. GEP-NENs encompass a wide spectrum of entities, from very indolent tumors to highly aggressive carcinomas. They represent a challenge for the oncologist and a correct diagnostic approach is crucial for the management of patients. The nomenclature and classification of these tumors have been a matter of debate for more than a century, since their first description by Siegfried Oberdorfer. The last WHO classification provided a robust and easy-to-use tool to prognostically stratify GEP-NENs, based on morphological aspects and on proliferation rate. This review examines current approaches to the diagnosis and prognostic classification of GEP-NENs, focusing on the critical use of morphological parameters and immunohistochemical stainings, including diagnostic, site-specific and prognostic markers. The key issues of the current classification are addressed, including the emerging topics about cases with discordant morphology and proliferative index. Finally, we attempted to highlight the diagnostic pitfalls and the caveats in the use of immunohistochemical stains.

Introduction: Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors of the gastrointestinal tract, which are characterized in the majority of cases by activating mutations in KIT and platelet-derived growth factor receptor alpha (PDGFRA). The introduction of tyrosine kinase inhibitors has revolutionized the management of patients with metastatic GIST. However, complete surgical resection remains the mainstay of management for those with localized disease. Recently, three large trials have confirmed the benefit of adjuvant imatinib therapy in patients who were at high risk of recurrence following complete resection. In this setting, it is critical that oncologists understand the various GIST risk assessment criteria and be able to apply these methods to accurately assess the risk of recurrence and the need for adjuvant imatinib therapy., Purpose: The aim of this review is to outline the risk stratification systems currently available to oncologists who are treating patients with GIST, so they can be optimally applied for clinical decision-making.

Purpose of Review: Knowledge related to gastrointestinal stromal tumor (GIST) in the setting of nonhereditary and hereditary multiple tumor syndromes continues to expand. This review describes associations between sporadic GIST and second malignancies, as well as new contributions to our knowledge about hereditary GIST multiple tumor syndromes., Recent Findings: Sporadic GIST patients have increased risk of developing synchronous/metachronous cancers, including nonhematologic and hematologic malignancies. Data suggest these associations are nonrandom, more prevalent in men and increase with age. New adrenal tumors have also been associated with nonhereditary Carney's triad. Meanwhile, understanding of the molecular basis of heritable GIST syndromes has improved. Several new familial GIST kindreds have been reported, including those with germline KIT and PDGFRα mutations. Knowledge about succinate dehydrogenase (SDH) deficiency and mutations in hereditary GIST syndromes has expanded. It is now known that neurofibromatosis-1-associated GISTs are SDHB-positive, whereas Carney-Stratakis syndrome-associated GISTs are SDHB-deficient with underlying germline mutations in SDH subunits A-D., Summary: Recognition and early diagnosis of GIST syndromes allows for improved comprehensive medical care. With additional understanding of the molecular pathogenesis of GIST multiple tumor syndromes, we can refine our screening programs and management of these patients and their families.

Poorly differentiated neuroendocrine carcinomas (PDNECs) of the gastroenteropancreatic system (GEP) are a heterogeneous group of aggressive malignancies with a high propensity for distant metastases and an ominous prognosis. They have traditionally been divided into small and large cell subtypes on morphological grounds. However, histological diagnosis needs to be supported by immunohistochemistry to avoid possible misdiagnoses either with the more frequent poorly differentiated adenocarcinomas and squamous cell carcinomas or with lymphomas and mesenchymal neoplasms. Although it is well known that GEP PDNECs are associated with a poor prognosis, data from some published studies seem to suggest that there is a fraction of patients with PDNECs who have better survival than expected. GEP PDNECs are currently classified according to the criteria proposed in the 2010 WHO classification. They are simply called neuroendocrine carcinomas (NECs) and are defined by mitotic count >20 × 10 HPF and/or Ki-67 labeling index >20 %. However, a few recent papers have indicated that some NECs, as defined by the 2010 WHO scheme, do not show a poorly differentiated morphology as expected. This category seems to show a better prognosis and, especially, does not respond to cisplatin-based chemotherapy, which represents the goal standard therapeutic approach to high-grade PDNECs. In the present review, the main morphological, immunohistochemical, and prognostic features will be discussed as well as the opportunity to introduce a new category characterized by well to moderately differentiated morphology associated with high proliferation (mitotic count >20 × 10 HPF and/or Ki-67 index >20 %).

Background and Aim: Little is known about the clinicopathological characteristics of primary gastrointestinal T-cell lymphomas (PGITL). This study evaluated the clinical and endoscopic features of the pathological subtypes of PGITL., Methods: Forty-two lesions in 36 patients with PGITL were assessed, including 15 enteropathy-associated T-cell lymphomas (EATL), 13 peripheral T-cell lymphomas (PTCL), 10 NK/T-cell lymphomas (NK/TL), and four anaplastic large cell lymphomas (ALCL)., Results: PTCL occurred more frequently in the stomach and duodenum and NK/TL more frequently in the small and large intestines (P = 0.009). The endoscopic features of the four subtypes were similar (P = 0.124). Fifteen of 41 lesions (36.6%) were Epstein-Barr virus (EBV) positive, with NK/TL more likely to be EBV positive than the other types (P < 0.001). First endoscopy and first computed tomography (CT) scan indicated that 65.4% and 51.4% of the lesions, respectively, were malignant, and that 43.2% and 42.3%, respectively, were GI lymphomas. The two modalities together correctly diagnosed about half of the lesions before biopsy. Intestinal perforation was associated with small bowel location (P < 0.001) and infiltrative type (P = 0.009), and was more common in NK/TL than in the other subtypes (P = 0.015). Multivariate analysis showed that higher international prognosis index (P = 0.008) and the presence of complications (P = 0.006) were associated with poor prognosis. Survival was poorer in patients with small bowel lesions than with lesions at other locations (P = 0.048)., Conclusions: The four main pathological types of PGITL differed in clinical characteristics. As PGITL was often not diagnosed by initial endoscopic or radiological examination, a high index of suspicion is necessary to ensure its early diagnosis., (© 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.)

Gastrointestinal lymphomas can be difficult to diagnose, particularly in small samples, when early in development, or when of unusual types. In this review, we describe lymphoid proliferations in the gastrointestinal tract in a location-based manner, including, mouth, esophagus, stomach, small intestine, and large bowel. For the purpose of differential diagnosis, benign mimics of lymphoma are also described. Lymphoma types that are specifically addressed include plasmablastic, extranodal natural killer/T-cell-nasal type, extranodal marginal zone lymphoma (eg, mucosa-associated lymphoid tissue lymphoma), diffuse large B cell, primary follicular of small intestine, enteropathy-associated T cell, and Burkitt and mantle cell. Immunohistochemical markers useful in the diagnostic approach are elaborated in detail., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Invasive micropapillary carcinoma (IMPC) is a rare histological type of tumor, first described in invasive ductal breast cancer, than in malignancies in other organs such as lungs, urinary bladder, ovaries or salivary glands. Recent literature data shows that this histological lesion has also been found in cancers of the gastrointestinal system. The micropapillary components are clusters of neoplastic cells that closely adhere to each other and are located in distinct empty spaces. Moreover, clusters of neoplastic cells do not have a fibrous-vascular core. The IMPC cells show reverse polarity resulting in typical ''inside-out'' structures that determines secretary properties, disturbs adhesion and conditions grade of malignancy in gastrointestinal (GI) tract. Invasive micropapillary carcinoma in this location is associated with metastases to local lymph nodes and lymphovascular invasion. IMPC can be a prognostic factor for patients with cancers of the stomach, pancreas and with colorectal cancer since it is related with disease-free and overall survival. The purpose of this review is to present the characterization of invasive micropapillary carcinoma in colon, rectum, stomach and others site of GI tract, and to determine the immunohistological indentification of IMPC in those localization.

This paper provides a personal pathologist's view of how neuroendocrine tumors (NET) were perceived and defined in the last quarter of a century. In years when the Helicobacter pylori, omeprazole and the adenoma-carcinoma sequence in colon carcinogenesis significantly impacted on gastrointestinal (GI) pathology daily practice, neuroendocrine neoplasms of the GI tract passed from the original carcinoid definition to the current NET and neuroendocrine carcinoma (NEC) definitions. The development of different concepts, basic tumor biology knowledge, tools for pathology diagnosis and the various World Health Organization (WHO) classifications from 1980 through 2010 are briefly reviewed and discussed.

There is a paucity of preclinical models that simulate the development of ovarian tumors in humans. At present, the egg-laying hen appears to be the most promising model to study the spontaneous occurrence of ovarian tumors in the clinical setting. Although gross classification and histologic grade of tumors have been used prognostically in women with ovarian tumors, there is currently no single system that is universally used to classify reproductive tumors in the hen. Four hundred and one 192-wk-old egg-laying hens were necropsied to determine the incidence of reproductive tumors using both gross pathology and histologic classification. Gross pathologic classifications were designated as follows: birds presenting with ovarian tumors only (class 1), those presenting with oviductal and ovarian tumors (class 2), those with ovarian and oviductal tumors that metastasized to the gastrointestinal tract (class 3), those with ovarian and oviductal tumors that metastasized to the gastrointestinal tract and other distant organs (class 4), those with oviductal tumors only (class 5), those with oviductal tumors that metastasized to other organs with no ovarian involvement (class 6), and those with ovarian tumors that metastasized to other organs with no oviductal involvement (class 7), including birds with gastrointestinal tumors and no reproductive involvement (GI only) and those with no tumors (normal). Histopathologic classifications range from grades 1 to 3 and are based on mitotic developments and cellular differentiation. An updated gross pathology and histologic classification systems for the hen reproductive malignancies provides a method to report the range of reproductive tumors revealed in a flock of aged laying hens.

The ideal management of NET must be addressed on a case-by-case basis, with consideration given to patient factors, disease burden, and clinical tumor activity. Outcome improvement for LT in the setting of metastatic disease requires better characterization of the biological behavior of NETs and further identification of factors to be included in the selection criteria. Box 3 summarizes the many areas that have been, and are currently, undergoing investigation. LT as an attempt for cure rather than palliation is a justified treatment option for well-selected patients with metastatic neuroendocrine tumors of the pancreas and GI system. Optimization of pretransplantation staging and patient management algorithms, patient selection, and posttransplant management options are areas that need to be better defined. Further investigations for defining reproducible prognostic factors, consistent histopathologic evaluation, and uniform preoperative staging and site-specific data are needed. With the advancement of newer treatment modalities, it is necessary to define the role of LT along with the optimal perioperative management of existing and recurrent disease.

The authors suggest an original method of endobiliary stenting with laparoscopic assistance for reduction of obstructive jaundice in patients with non-operative tumors of hepatopancreaduodenal zone in the case of impossibility of performance of percutaneous or endoscopic decompression of the bile ducts. A recanalization of tumor stricture was carried out with the aid of laparoscopic assistance. A self-expandable metal stent with polymeric covering was implanted in the bile ducts. The proposed method was applied in 5 cases. An adequate decompression of the bile ducts was noted in all cases. The patient's condition was good after surgery. There weren't any cases of serious complications or hospital lethality.