• They originate in amine precursor uptake and decarboxylation (APUD) cells of the gastroenteropancreatic endocrine system and in adrenal or extra-adrenal neurogenic sites. (medscape.com)
  • Islet cells commonly are referred to as APUD cells, a name derived from their high amine content and capacity for amine precursor uptake with decarboxylation. (medscape.com)
  • In 1980, the World Health Organization (WHO) applied the term carcinoid to all tumors of the diffuse endocrine system (synonymous with amine precursor uptake and decarboxylation [APUD] and neuroendocrine cell system). (medscape.com)
  • however, tumors can originate from any cell of the amine precursor uptake and decarboxylation system and, therefore, produce several intestinal hormones. (medscape.com)
  • The detailed study of neuroendocrine cells by Pearse ( 3 , 4 ) led to the development of the concept of amine precursor uptake and decarboxylation (APUD). (basicmedicalkey.com)
  • Pancreatic non-beta-cell hyperplasia is rare but has been reported in children. (medscape.com)
  • Pancreatic islet cells are part of the diffuse neuroendocrine system of the gut and pancreatic endocrine system. (medscape.com)
  • Pancreatic neuroendocrine tumors may be functional or nonfunctional. (medscape.com)
  • Pancreatic islet cell tumors may secrete 2 or more polypeptide hormones. (medscape.com)
  • 10] In contrast to individuals with VIP-secreting pancreatic tumors, patients with neurogenic lesions generally have normal serum levels of pancreatic polypeptide, gastrin, insulin, and somatostatin. (medscape.com)
  • The production of somatostatin by the pancreatic islets, which regulates insulin and glucagon production in neighboring islet cells, is an example of paracrine regulation. (basicmedicalkey.com)
  • In pancreatic islets, GLUT2 allows a rapid equilibration of glucose between the extracellular space and the interior of the cells and it may play a crucial role in the glucose signaling mechanism leading to insulin secretion (43). (justia.com)
  • pancreatic cells to glucose remains debated. (justia.com)
  • In children and adolescents, VIP is produced mainly by ganglioneuromas, ganglioneuroblastomas, neurofibromas, or other tumors in the adrenal area (the most common location). (medscape.com)
  • The steroid-producing endocrine cells of the adrenal cortex, ovary, and testis, as well as the thyroid hormone-producing follicular cells in the thyroid gland, do not form part of the DNS. (basicmedicalkey.com)
  • Approximately 10% of neuroendocrine tumors of the gastrointestinal (GI) tract (except carcinoids) are VIPomas. (medscape.com)
  • Feyrter ( 2 ) considered the clear cells of the gastrointestinal tract to be peripheral endocrine or paracrine cells. (basicmedicalkey.com)
  • However, to communicate effectively with clinicians, the term carcinoid tumor can still be used in parenthesis for neoplasms of the gastrointestinal tract and lungs. (basicmedicalkey.com)
  • Islet cell tumors in this group are often multiple and malignant. (medscape.com)
  • Malignant carcinoid syndrome occurs in fewer than 10% of patients with a carcinoid tumor. (medscape.com)
  • The name was chosen to separate these tumors from ordinary malignancies (carcinomas), but by the 1950s, the fact that carcinoids could be malignant was obvious, thanks to Erspamer and Asero (1952), who identified serotonin production by carcinoid tumors. (medscape.com)
  • Carcinoids do not produce the malignant carcinoid syndrome until they are no longer confined to the small bowel or mesentery, perhaps because the liver breaks down the secretory products of tumors restricted to those locations. (medscape.com)
  • Most are malignant except the insulin-producing tumors (INSULINOMA). (lookformedical.com)
  • It is also employed for the detection of malignant tumors including those of the brain, liver, and thyroid gland. (lookformedical.com)
  • In pathology, an apudoma is an endocrine tumour that arises from an APUD cell from structures such as the ampulla of Vater. (wikipedia.org)
  • Neural crest cells are precursors of APUDoma and neurogenic cells. (medscape.com)
  • APUDOMA is a general term collectively applied to tumors associated with APUD cells. (wakehealth.edu)
  • and asthma attacks-caused by vasoactive hormones secreted by metastases from carcinoid tumors. (medscape.com)
  • Paracrine regulation refers to the production of amines and hormones by cells that exert a local effect on the target cells by diffusion through the extracellular space. (basicmedicalkey.com)
  • When their protective barriers are missing, hormones and cells that are present during inflammatory processes induce activation of clasts which, when unbalanced, no longer perform physiological bone remodeling and begin to provoke an immunopathological response that causes dental resorption. (bvsalud.org)
  • The tumors are usually greater than 3 cm in diameter at the time of diagnosis and are found primarily in the body and tail of the pancreas. (medscape.com)
  • No universally agreed-upon algorithm exists in the radiologic investigation of pancratic neuroendocrine (islet cell) tumors of the pancreas. (medscape.com)
  • Evidence has shown that endoscopic ultrasonography (EUS) can be used to accurately diagnose and localize primary endocrine tumors of the pancreas, especially insulinomas and gastrinomas. (medscape.com)
  • Tumors or cancer of the PANCREAS. (lookformedical.com)
  • Local tumor resection is the treatment of choice. (medscape.com)
  • Amyloid deposits are not uncommon in endocrine neoplasms and can also occur in pituitary tumors. (scirp.org)
  • Methods of analysis of tumors of the DNS are also presented because some of these techniques are indispensable for the diagnosis of many neuroendocrine neoplasms. (basicmedicalkey.com)
  • The cells and neoplasms of the neuroendocrine and paracrine systems make up the DNS. (basicmedicalkey.com)
  • The principal cells and neoplasms that form the DNS are listed in Table 11.1 . (basicmedicalkey.com)
  • Although the term carcinoid tumor has been broadly used to refer to many neoplasms derived from the DNS ( 9 ), this term is being replaced by neuroendocrine neoplasms. (basicmedicalkey.com)
  • instead, WDHA syndrome is usually associated with VIP-secreting neurogenic tumors involving the retroperitoneum and mediastinum. (medscape.com)
  • VIPomas are neuroendocrine tumors that secrete vasoactive intestinal peptide (VIP) autonomously. (medscape.com)
  • They may manifest as sporadic tumors or as part of certain syndromes, including multiple endocrine neoplasia type 1 (MEN 1) and von Hippel-Lindau (VHL) disease. (medscape.com)
  • Carcinoid tumors and related syndromes may be a part of multiple endocrine neoplasia . (medscape.com)
  • On the other hand, insulinoma cells that had lost their normal glucose responsiveness have low GLUT2 content, but some glucose sensitivity may be recovered after reintroducing GLUT2 expression through stable transfection of these cells (10,16). (justia.com)
  • If a patient is thought to have carcinoid syndrome, blood and urine tests must be performed to determine levels of bioactive substances secreted by carcinoid tumors. (medscape.com)
  • They were historically thought to be derived from neural crest cells, but this has since been shown to be untrue (see neuroendocrine tumor).The term dates back to at least 1975. (wikipedia.org)
  • This is a property of endocrine cells of neural and non-neural origin. (wakehealth.edu)
  • Although the APUD concept provided a unifying theory for explaining some endocrine diseases and ectopic hormone productions, the hypothesis that the cells were all of neural crest origin, as postulated by Pearse, was later disproved by the experiments of LeDouarin ( 5 ) and others. (basicmedicalkey.com)
  • Typically, 90% of carcinoid tumors originate from the distal ileum or appendix (the embryologic midgut. (medscape.com)
  • Its therapeutic use is limited to the treatment of hypercalcemia and Paget's osteopathy, and as a tumor marker in medullary carcinoma. (teknon.es)
  • Its exact pathogenesis is still not fully understood, but it may have systemic origins associated with debilitating infections, endocrine disorders, bone disease (Paget's disease) or radiotherapy, but it can also be idiopathic 2 . (bvsalud.org)
  • Complete surgical removal of all tumor tissues, when feasible, is the best treatment. (medscape.com)
  • Although nonfunctional islet cell tumors are not uncommon at autopsy, most islet cell tumors with clinical manifestations are functional. (medscape.com)
  • The DNS consists of a wide variety of cells that are present in the central and peripheral nervous system and in many classic endocrine organs ( Table 11.1 ). (basicmedicalkey.com)
  • Carcinoid tumors arise from neuroendocrine cells, which are widespread in the human body, especially in the organs derived from the primitive intestine. (medscape.com)
  • In 1914, Gosset and Masson demonstrated that carcinoid tumors might arise from enterochromaffin cells (Kulchitsky cell) within glands of Lieberkühn using silver impregnation techniques. (medscape.com)
  • This article reviews the role of imaging in the management of islet cell tumors. (medscape.com)
  • Imaging studies also must be performed to detect the sites of either primary tumors or metastases. (medscape.com)
  • An imaging technique using compounds labelled with short-lived positron-emitting radionuclides (such as carbon-11, nitrogen-13, oxygen-15 and fluorine-18) to measure cell metabolism. (lookformedical.com)
  • Most of these tumors produce 5-hydroxytryptamine, which, in physiologic conditions, is taken up and stored in the platelets while the excesses are inactivated in the liver and lung and transformed into 5-hydroxyindoleacetic acid (5-HIAA). (medscape.com)
  • Tumors or cancer of the LIVER. (lookformedical.com)
  • insulin-secreting cells, the basolateral membrane of intestinal and kidney absorptive cells, in hepatocytes and in a subset of neurons (21,31,44). (justia.com)
  • In 1928, Masson established characterization of carcinoids as argentaffin cell tumors. (medscape.com)
  • Some of the less common DNS tumors are presented, along with differential diagnoses, because the more common lesions are covered in detail in other areas of the text. (basicmedicalkey.com)
  • [ 8 ] Approximately 5% of VIPomas are associated with multiple endocrine neoplasia (MEN) type 1 syndrome . (medscape.com)
  • which reports a mortality rate of 11% , not caused by the tumour but solely by the chemotherapy. (beatingcancercenter.com)
  • Functioning tumors produce a clinical syndrome as a result of excessive hormone production. (medscape.com)
  • Amine storage and function in peptide hormone-producing cells. (uni-bielefeld.de)
  • Clinical features of the syndrome depend on tumor cell type. (medscape.com)
  • C. Wegner, G. Teuchert-Noodt, and R.R. Dawirs, "Demonstration of dopamine immunoreactivity in open and closed type endocrine cells of gerbil (Meriones unguiculatus) stomach", LIFE SCIENCES , vol. 59, 1996, pp. 1407-1413. (uni-bielefeld.de)
  • Functioning tumors usually are small at presentation, and localizing these tumors can be challenging to the radiologist. (medscape.com)
  • Nonfunctioning tumors usually are larger and present because of their size or metastatic spread. (medscape.com)
  • We present a case of prolactinoma in a 54-year old male patient who presented with pressure effects because of the tumor, as head ache and bi-temporal hemianopsia. (scirp.org)
  • [ 4 ] but Oberndorfer called a group of small, benign-appearing tumors karzinoide tumoren (carcinoid) for the first time in 1907. (medscape.com)
  • These cells share the ability to produce many biologically active amines, peptides, and other substances. (basicmedicalkey.com)
  • MRI Brain scan was done to identify the tumor. (scirp.org)
  • A section of a rare lymph node metastasis from adenocarcinoid tumor (250 X). Image courtesy of Professor Pantaleo Bufo, University of Foggia, Italy. (medscape.com)
  • Rare catecholamine-secreting tumor derived from chromaffin cells. (preparingtobecome.com)
  • Absence of dopamine-beta-hydroxylase in some catecholamine-containing sympathetic ganglion cells of the dog: evidence for dopaminergic autonomic neurones. (uni-bielefeld.de)
  • Dopamine and the regulation of cell proliferation in gerbil (Meriones unguiculatus) pyloric mucosa. (uni-bielefeld.de)
  • The cells of the DNS have also been referred to historically as paraneurons ( 1 ). (basicmedicalkey.com)
  • The current neuroendocrine classification of cells and tumors uses immunohistochemical (IHC), ultrastructural, and molecular biologic features to define members of the DNS ( 6 , 7 and 8 ). (basicmedicalkey.com)
  • No medical treatment was given but the tumor recurred after 6 months and a repeat surgery was done for total excision. (scirp.org)
  • You also have to find out the presence or appearance of tumors, duration of it, their growth rate and the presence of pain. (teknon.es)