ARX, PDX1, ISL1, and CDX2 Expression Distinguishes 5 Subgroups of Pancreatic Neuroendocrine Tumors With Correlations to Histology, Hormone Expression, and Outcome.

Many pancreatic neuroendocrine tumors (PanNETs) fall into 2 major prognostic subtypes based on DAXX/ATRX-induced alternative lengthening of telomerase phenotype and alpha- and beta-cell-like epigenomic profiles. However, these PanNETs are still flanked by other PanNETs that do not fit into either subtype. Furthermore, despite advanced genotyping, PanNETs are generally not well-characterized in terms of their histologic and hormonal phenotypes.

PITX2 as a Sensitive and Specific Marker of Midgut Neuroendocrine Tumors: Results from a Cohort of 1157 Primary Neuroendocrine Neoplasms.

As neuroendocrine tumors (NETs) often present as metastatic lesions, immunohistochemical assignment to a site of origin is one of the most important tasks in their pathologic assessment. Because a fraction of NETs eludes the typical expression profiles of their primary localization, additional sensitive and specific markers are required to improve diagnostic certainty. We investigated the expression of the transcription factor Pituitary Homeobox 2 (PITX2) in a large-scale cohort of 909 NET and 248 neuroendocrine carcinomas (NEC) according to the immunoreactive score (IRS) and correlated PITX2 expression groups with general tumor groups and primary localization.

High expression of insulinoma-associated protein 1 (INSM1) distinguishes colorectal mixed and pure neuroendocrine carcinomas from conventional adenocarcinomas with diffuse expression of synaptophysin.

Complementary to synaptophysin and chromogranin A, insulinoma-associated protein 1 (INSM1) has emerged as a sensitive marker for the diagnosis of neuroendocrine neoplasms. Since there are no comparative data regarding INSM1 expression in conventional colorectal adenocarcinomas (CRCs) and colorectal mixed adenoneuroendocrine carcinomas/neuroendocrine carcinomas (MANECs/NECs), we examined INSM1 in a large cohort of conventional CRCs and MANECs/NECs. In conventional CRC, we put a special focus on conventional CRC with diffuse expression of synaptophysin, which carry the risk of being misinterpreted as a MANEC or a NEC.

Renal neuroendocrine tumors: clinical and molecular pathology with an emphasis on frequent association with ectopic Cushing syndrome.

Renal neuroendocrine tumors (RenNETs) are rare malignancies with largely unknown biology, hormone expression, and genetic abnormalities. This study aims to improve our understanding of the RenNETs with emphasis of functional, hormonal, and genetic features. Surgically resected RenNETs (N = 13) were retrieved, and immunohistochemistry and next-generation sequencing (NGS) were performed in all cases.

An integrated cellular and molecular model of gastric neuroendocrine cancer evolution highlights therapeutic targets.

Gastric neuroendocrine carcinomas (G-NEC) are aggressive malignancies with poorly understood biology and a lack of disease models. Here, we use genome sequencing to characterize the genomic landscapes of human G-NEC and its histologic variants. We identify global and subtype-specific alterations and expose hitherto unappreciated gains of MYC family members in a large part of cases.

One hundred years after the discovery of insulin and glucagon: the history of tumors and hyperplasias that hypersecrete these hormones.

One century ago, in 1922, Frederick G Banting, Charles H Best, James B Collip and John J R Macleod first published their experiments resulting in the isolation of a hypoglycemic factor, named insulin, from a solution extract from a dog's pancreas. One year later, in 1923, a hyperglycemic factor named glucagon was isolated by Charles P Kimball and John R Murlin. In the following years, it could be demonstrated that pancreatic islet alpha- and beta-cell neoplasms and hyperplasias could inappropriately secrete excessive amounts of these two hormones.

Pathological features in non-neoplastic congenital and adult hyperinsulinism: from nesidioblastosis to current terminology and understanding.

Nesidioblastoma and nesidioblastosis were terms given to neoplastic and non-neoplastic lesions of the pancreas associated with pancreatogenous hyperinsulinaemic hypoglycaemia. While nesidioblastoma was rapidly replaced by islet cell tumour, nesidioblastosis, defined as the proliferation of islet cells budding off from pancreatic ducts, was the diagnostic term associated with congenital hyperinsulinism of infancy (CHI) and adult non-neoplastic hyperinsulinaemic hypoglycaemia (ANHH). When it was shown that nesidioblastosis was not specific for CHI or ANHH, it was no longer applied to CHI but kept for the morphological diagnosis of ANHH.

Glucagon cell hyperplasia and neoplasia: a recently recognized endocrine receptor disease.

Glucagon cell hyperplasia and neoplasia (GCHN) is the name of an endocrine receptor disease, whose morphology was first described in 2006. Three years later, this rare disease was found to be to be caused by an inactivating mutation of the glucagon receptor (GCGR) gene. Functionally, the genetic defect mainly affects glucagon signaling in the liver with changes in the metabolism of glycogen, fatty acids and amino acids.

Gene fusions are frequent in ACTH-secreting neuroendocrine neoplasms of the pancreas, but not in their non-pancreatic counterparts.

Ectopic Cushing syndrome is a rare clinical disorder resulting from excessive adrenocorticotrophic hormone (ACTH) produced by non-pituitary neoplasms, mainly neuroendocrine neoplasms (NENs) of the lung, pancreas, and gastrointestinal tract, and other less common sites. The genetic background of ACTH-producing NENs has not been well studied. Inspired by an index case of ACTH-producing pancreatic NEN carrying a gene fusion, we postulated that ACTH-producing NENs might be enriched for gene fusions.

Acute and Chronic Alcoholic Pancreatitis, Including Paraduodenal Pancreatitis.

Context.—: In the last 2 decades there has been significant progress in typing and recognition of pancreatitis, a necroinflammatory and fibroinflammatory process of multifactorial origin.

Objective.

Neuroendocrine tumor G3 of bronchopulmonary origin and its classification.

Neuroendocrine tumors (NET) with high proliferative activity (Ki-67 index >20% and/or mitotic counts >2 mm ) are defined as NET G3 in the 2019 World Health Organization (WHO) classification of digestive system neuroendocrine neoplasms (NENs). NETs G3 occur mostly in the pancreas, colon, rectum, and stomach and only rarely in the small intestine and the appendix. In the bronchopulmonary system, similar tumors have also been recognized and were mostly classified as atypical carcinoid (AC) or large cell neuroendocrine carcinoma.

MCL1 as putative target in pancreatoblastoma.

Pancreatoblastoma (PB) is a rare tumor of the pancreas. In case of metastases, the treatment options are sparse and targeted approaches are not developed. We here evaluate MCL1 amplification as a putative target in PB.

ENETS standardized (synoptic) reporting for neuroendocrine tumour pathology.

In recent years the WHO classification of neuroendocrine neoplasms (NEN) has evolved. Nomenclature as well as thresholds for grading have changed leading to potential confusion and lack of comparability of tumour reports. Therefore, the European Neuroendocrine Tumour Society (ENETS) has set-up an interdisciplinary working group to develop templates for a pathology data set for standardised reporting of NEN.

Neuroendocrine Differentiation in Conventional Colorectal Adenocarcinomas: Incidental Finding or Prognostic Biomarker?

Background: Colorectal mixed adenoneuroendocrine carcinomas (MANECs) are clinically highly aggressive neoplasms. MANECs are composed of variable adenocarcinoma components combined with morphologically distinct neuroendocrine carcinoma components, which are confirmed by synaptophysin immunohistochemistry, the gold standard marker of a neuroendocrine differentiation. However, the biological behavior of adenocarcinomas that express synaptophysin but do not show a typical neuroendocrine morphology remains unclear.

Neuroendocrine neoplasms of the pancreas: diagnosis and pitfalls.

Common to neuroendocrine neoplasms of the pancreas is their expression of synaptophysin, chromogranin A, and/or INSM1. They differ, however, in their histological differentiation and molecular profile. Three groups can be distinguished: well-differentiated neuroendocrine neoplasms (neuroendocrine tumors), poorly differentiated neuroendocrine neoplasms (neuroendocrine carcinomas), and mixed neuroendocrine-non-neuroendocrine neoplasms.

An analysis of 130 neuroendocrine tumors G3 regarding prevalence, origin, metastasis, and diagnostic features.

Limited data exist on high-grade neuroendocrine tumors (NETs G3) which represent a new category among neuroendocrine neoplasms (NEN). We analyzed NETs G3 in a consultation series regarding prevalence, origin, metastasis, and diagnostic problems. Based on the WHO classification of digestive system tumors, 130 NETs G3 (9%) were identified in 1513 NENs.

[Ductal adenocarcinoma of the pancreas: subtypes and molecular pathology].

Ductal adenocarcinoma is the most common tumor of the pancreas. Although relatively rare, it poses one of the greatest oncological challenges because of its poor prognosis, which has so far only slightly improved. Progress has been made in the more precise classification and standardization of the morphological assessment.

Mesenchymal/non-epithelial mimickers of neuroendocrine neoplasms with a focus on fusion gene-associated and SWI/SNF-deficient tumors.

Mimickers of neuroendocrine neoplasms (NEN) include a number of important pitfall tumors. Here, we describe our experience with mesenchymal mimics of NENs to illustrate their spectrum and draw the attention particularly to a group of mesenchymal/non-epithelial neoplasms (MN) that combine epithelioid histology with neuroendocrine (NE-) features and peculiar genetic abnormalities. In a consultation series of 4498 cases collected between 2009 and 2021, 2099 neoplasms expressing synaptophysin and/or chromograninA were reviewed and analyzed.

Intra-abdominal EWSR1/FUS-CREM-rearranged malignant epithelioid neoplasms: two cases of an emerging aggressive entity with emphasis on misleading immunophenotype.

CREB family (CREB1, ATF1, and CREM) gene fusions are defining markers in diverse mesenchymal neoplasms (clear cell sarcoma, angiomatoid fibrous histiocytoma, and others). However, neoplasms harboring EWSR1-CREM/FUS-CREM fusions are rare and poorly characterized. We describe two cases (55-year-old male with 7.

Whole Exome Sequencing of Biliary Tubulopapillary Neoplasms Reveals Common Mutations in Chromatin Remodeling Genes.

The molecular carcinogenesis of intraductal tubulopapillary neoplasms (ITPN), recently described as rare neoplasms in the pancreato-biliary tract with a favorable prognosis despite a high incidence of associated pancreato-biliary adenocarcinoma, is still poorly understood. To identify driver genes, chromosomal gains and losses, mutational signatures, key signaling pathways, and potential therapeutic targets, the molecular profile of 11 biliary and 6 pancreatic ITPNs, associated with invasive adenocarcinoma in 14/17 cases, are studied by whole exome sequencing (WES). The WES of 17 ITPNs reveals common copy number variants (CNVs) broadly distributed across the genome, with recurrent chromosomal deletions primarily in 1p36 and 9p21 affecting the tumor suppressors and , respectively, and gains in 1q affecting the prominent oncogene .