Pancreatic endocrine disorders and multiple endocrine neoplasia

Pancreatic neuroendocrine tumours (islet-cell tumours) are rare and usually sporadic, but they may be associated with complex familial endocrine cancer syndromes. Recognized types of pancreatic neuroendocrine tumours are those that are non-functioning (often advanced at diagnosis and presenting with mass effects due to the absence of symptoms attributable to hormone hypersecretion), insulinoma (the most frequent type), and others including gastrinoma, VIPoma, and glucagonoma. The following should be considered in addition to the symptomatic treatments: surgical resection—the only curative treatment, but not possible in many cases; tyrosine kinase inhibitors which inhibit specific kinases involved in tumour cell proliferation, growth, and angiogenesis; mammalian Target of Rapamycin (mTOR) inhibitors; peptide-receptor radionuclide therapy (radiolabelled somatostatin analogues).

MEN1 Syndrome and Hibernoma: An Uncommonly Recognised Association?

MEN1 syndrome is known to classically result in parathyroid, pituitary, and pancreatic islet cell tumours. However, the potential association of MEN1 syndrome with hibernoma, a benign tumour with differentiation towards brown fat, is far less well known, despite their genetic profile both being linked to deletion of theMEN1gene. Herein, we describe a case with its key radiological and pathological findings.

Gastrinoma

Gastrin is a gastrointestinal hormone, produced predominantly by the G cells of the gastric antrum and duodenum, although small amounts of gastrin have been isolated in the pituitary and some vagal nerve fibres. The biologically active forms of gastrin include carboxy-amidated gastrin-17 and carboxy-amidated gastrin-34, which bind mainly to the cholecystokinin (CCK)-2 receptor. The main role of amidated gastrin is the stimulation of gastric acid secretion by regulation of histamine release from the gastric enterochromaffin-like (ECL) cells, while it may also have a trophic effect on gastric mucosa. There is evidence that the precursor forms of gastrin, such as progastrin and glycine-extended gastrin, are also of biological importance, binding to a separate CCK-C receptor. These precursor may induce cellular and tumour growth and they are implicated in several cancers, such as colon and pancreatic adenocarcinomas. Gastrinomas represent a group of functional pancreatic neuroendocrine tumours, characterized by autonomous release of gastrin by the tumour cells, which results in symptoms not only due to the tumour growth per se, but also to gastric acid hypersecretion. In 1955, at the annual meeting of American Surgical Association, Robert M. Zollinger and Edwin H. Ellison presented a study entitled Primary Peptic Ulcerations of the Jejunum Associated with Islet Cell Tumour of the Pancreas. They proposed a new clinical syndrome of: (1) ulceration in unusual locations in the upper gastrointestinal tract or recurrent ulcerations; (2) gastric acid hyperseretion; and (3) non-β‎ islet cell tumours of the pancreas. However, the potent gastric secretagogue for the Zollinger–Ellison syndrome was not identified until 1960, when Rodney Gregory and Hilda Tracy of the University of Liverpool discovered that the extract from the pancreas of a patient with Zollinger–Ellison syndrome was the hormone gastrin. Thus, these pancreatic tumours were termed ‘gastrinomas’.

Pancreatic endocrine disorders and multiple endocrine neoplasia

Pancreatic neuroendocrine tumours (islet cell tumours) are rare and usually sporadic, but they may be associated with complex familial endocrine cancer syndromes. Recognized types of pancreatic neuroendocrine tumours are those that are nonfunctioning (often advanced at diagnosis due to the absence of symptoms attributable to hormone hypersecretion), insulinoma (the most frequent type, see ...