1,721,293 research outputs found
Neuroendocrine neoplasia goes molecular — time for a change
No full textIn a cohort of 100 patients with neuroendocrine cancer, the use of NETest enabled earlier prediction of tumour progression and resulted in a reduction in the frequency of follow-up procedures. These outcomes are exciting and promising, but limited in value by the heterogeneity of the study cohort and by suboptimal assay sensitivity and specificity
Differentiation Versus Grade for Pancreatic Neuroendocrine Neoplasms
Full text linkContext.—: Pancreatic neuroendocrine neoplasia (panNEN) is a tumor disease with distinctive morphology and often poses diagnostic challenges. Objective.—: To present and discuss the current diagnostic criteria of PanNEN. Data sources.—: PanNENs are classified by the World Health Organization (WHO) criteria into well-differentiated neuroendocrine tumor (panNET) and poorly differentiated neuroendocrine carcinoma (panNEC) of large or small cell type. panNETs are graded as G1-G3 on the basis of their proliferation capacity by mitotic count and/or Ki-67 proliferation index. Differentiation and grading are overlapping tools essentially directed to the definition of tumor cell resemblance to the normal cell counterpart (differentiation) and its proliferation capacity (grading). Both tools aim at defining the panNEN malignant potential, and ultimately the overall and event-free survival. The 2 panNEN families mirror different molecular backgrounds. The panNET genotype consistently displays mutation/copy number variation of DAXX (death domain associated protein), ATRX (ATRX chromatin remodeler), and MEN1 (menin 1) genes, while in panNEC the usual cancer drivers TP53 (tumor protein 53), RB1 (RB transcriptional corepressor 1), and KRAS (KRAS proto-oncogene, GTPase) genes are mutated/abnormal. The more subtle differences measured by grade in panNET G1-G3 reflect a progressive gene disorder, with G3 often involving TP53. This rare genetic setting is usually associated with a difficult differential diagnosis between panNET G3 and panNEC. Immunohistochemistry for the informative genes DAXX, ATRX, TP53, RB1, P16 (cyclin-dependent kinase inhibitor 2A), and SST2 (somatostatin receptor 2) are the key to separating panNETG3 and panNEC; however, molecular investigation is often required and decisive. Nonetheless, ambiguous cases may remain unresolved. Conclusions.—: The WHO diagnostic criteria for panNEN are simple and effective tools for a clinically meaningful patient stratification. Areas of uncertainty remain and deserve further investigation
Endocrine hyperplasia and dysplasia in the pathogenesis of gastrointestinal and pancreatic endocrine tumors.
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25 Years of neuroendocrine neoplasms of the gastrointestinal tract
No full textThis 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
Neuroendocrine neoplasm update: toward universal nomenclature
No full textNeuroendocrine neoplasia is described in almost every tissue, either in the pure endocrine organs, the nerve structures or in the so-called diffuse neuroendocrine system. The current nomenclature contains time-honored widely accepted definitions; however, it is different according to anatomical sites. Diverse definitions may generate confusion and non-standard patient management. The International Agency for Research on Cancer – World Health Organization (IARC-WHO) proposed a framework for universal classification of neuroendocrine neoplasia. Evidence indicates that neuroendocrine cancer is composed by cells with a distinctive phenotype characterized by the expression of general and specific neuroendocrine markers. The neuroendocrine phenotype is indicated as descriptor of a unique cancer category, now recommended for all organs as Neuroendocrine Neoplasm. Evidence indicates that neuroendocrine neoplasia may be well or poorly differentiated, with diverse incidence and prevalence in different organs. It is proposed that the well differentiated neoplasm is universally defined neuroendocrine tumor (NET), and the poorly differentiated neoplasm neuroendocrine carcinoma (NEC). Evidence indicates that a cancer grading tool based on a proliferation measure by mitotic count, Ki67 % and/or necrosis assessment is useful to predict NET patient behavior. It is proposed to utilize this tool for grading NET universally, with site-specific cut-offs to be defined. It is also acknowledged that significant biological site-specific differences exist. It is recommended that current pathology reports contain this classification together with the current traditional classifiers. This IARC-WHO common classification framework for neuroendocrine neoplasm aims at uniformizing nomenclature toward different organs and at fostering the definition of a similar site-specific gene signature
The 2010 WHO classification of digestive neuroendocrine neoplasms: a critical appraisal four years after its introduction
No full textThis paper briefly illustrates the basis, rules of application, and present outcome of the current World Health Organization (WHO) classification for neuroendocrine neoplasms. Established in 2010 upon the proposal from the European Neuroendocrine Tumor Society (ENETS), the WHO 2010 fostered some definitional changes (most notably the use of neuroendocrine tumor (NET) instead of carcinoid) and indicated the tools of grading and staging. Specific rules for its application were also defined. The data generated from the use of WHO 2010 classification substantially endorsed its rules and prognostic efficacy. In addition, the application demonstrated some issues, among which are the possible re-definition of the cutoff for grading G1 vs G2, as well as the possible identification of cases with somewhat different clinical behavior within the G3 neuroendocrine cancer class. Overall, since the recent introduction of WHO 2010 grading and staging, it appears wise to keep the current descriptors to avoid unnecessary confusion and to generate comparable data. Homogenous data on large series are ultimately needed to solve such issues
Introduction to neuroendocrine neoplasms of the digestive system: definition and classification
No full text: Neoplasms characterized by the expression of markers of neuroendocrine differentiation in neoplastic cells are defined neuroendocrine. This broad definition comprises tumors found at different sites of the body with similar morphology but different behavior and genetic background. From a clinical standpoint neuroendocrine neoplasms may be functioning, when they give rise to unregulated secretion of hormones. Functioning tumors account for about one-third of neuroendocrine neoplasms. From a pathological standpoint neuroendocrine neoplasm are classified by cancer category, cancer families/classes, cancer types, cancer grade and cancer stage. The category identifies the cancer major trait and thus defined as neuroendocrine neoplasia (NEN) to comprise all families/classes of neuroendocrine cancer. The cancer family/types are neuroendocrine tumors (NET) as well differentiated, and neuroendocrine carcinoma (NEC) as poorly differentiated forms. Cancer grade, based on proliferation measure by mitotic count and Ki-67%, and cancer stage, based on tumor size and invasion (T), node deposits (N) and distant metastases (M), complete the pathological classification. Site-specific differences are the rule. Still missing is a genetic classification tool to complement current pathological descriptors
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