Die disseminierten (diffusen) endokrinen Zellen. Pathologie der endokrinen Organe. Berlin: Springer Berlin Heidelberg; 1981. pp. 1079-135. [DOI: 10.1007/978-3-642-67691-8_4]

Endocrine tumours of the gastrointestinal tract. Introduction: definition, historical aspects, classification, staging, prognosis and therapeutic options

Synonyms for gastroenteropancreatic endocrine tumours are 'endocrine tumours' and 'neuroendocrine tumours', and for pancreatic tumours 'islet cell tumours'. The term 'carcinoid' should only be used for endocrine tumours of the gastrointestinal tract and not for those of the pancreas. Endocrine tumours should be classified according to a recent World Health Organization proposal that provides clinically and prognostically important information. The prognosis of well-differentiated endocrine tumours is variable and, in general, favourable. However, we have few histological data from which to predict tumour growth and long-term prognosis in well-differentiated tumours. Poorly differentiated, small-cell tumours have an unfavourable prognosis. Patients with endocrine tumours have an increased risk of developing synchronous and metachronous non-endocrine malignancies. Most current treatment options are not supported by prospective, randomised and controlled trials.

The Gastroenteropancreatic Neuroendocrine Cell System and Its Tumors: The WHO Classification

Although well established in medical terminology, the term carcinoid is no longer adequate to cover the entire morphological and biological spectrum of neoplasms of the disseminated neuroendocrine cell system. Therefore, instead of carcinoid, the WHO classification published in 2000 uses the general terms neuroendocrine tumor and neuroendocrine carcinoma. In this review a classification of gastroenteropancreatic neuroendocrine tumors based on the WHO criteria is described. We also classify and comment on the most important tumor entities. On the basis of localization and of various morphological and biological criteria, we distinguish between benign neuroendocrine tumors, tumors with uncertain malignant potential, and tumors showing low-grade and high-grade malignancy.

Neuroendocrine tumors. A European view

A center in Belfast, Northern Ireland, has established a register for tumors of the gastroenteropancreatic endocrine system. Carcinoid tumors occur most frequently. Of the non-carcinoid tumors, insulinomas, gastrinomas, and unknown types have the highest incidence, with other types being extremely rare. The potentially remediable nature of the tumors is stressed, and frequently a good quality of life can be experienced even in the presence of metastatic disease. The syndromes are probably underdiagnosed as they present with clinical features for which there are more common explanations, and appropriate diagnostic methods are therefore not used. The management of the syndromes is reviewed with particular emphasis on the treatment of patients with inoperable disease. Histamine (H2)-receptor antagonist therapy has made an impact in Zollinger-Ellison syndrome, and streptozotocin and somatostatin analogues can control tumor growth and endocrine syndromes, respectively.

Duodenal and ampullary carcinoid tumors. A report of 12 cases with pathological characteristics, polypeptide content and relation to the MEN I syndrome and von Recklinghausen's disease (neurofibromatosis)

Twelve duodenal carcinoid tumours are presented, 4 of them located in the ampulla. Symptoms included the Zollinger-Ellison syndrome (4 patients), the carcinoid syndrome (1 patient), mechanical obstruction (3 patients), bleeding (1 patient) and abdominal pain (1 patient). Two further tumours were detected by chance. Three patients with the Zollinger-Ellison syndrome had additional endocrine tumours characteristic of the MEN I syndrome. In 2 of them the duodenal carcinoids were of very small size and were multiple. They were observed in close proximity to focal areas of endocrine cell hyperplasia. Immunohistochemical investigations showed gastrin and somatostatin to be the predominant polypeptide hormones produced by these tumours. No somatostatinoma syndrome was encountered. In half of our cases additional production of insulin, VIP or even calcitonin in smaller amounts was found. Two of our patients had cutaneous manifestations of von Recklinghausen's disease and in both of them the carcinoid was located in the ampulla. One of these patients also had a pheochromocytoma.

Chemical and immunochemical characterisation of substance P-like immunoreactivity and physalaemin-like immunoreactivity in a carcinoid tumour

Extracts of a carcinoid tumour, resected from the mid-portion of the ileum of a patient with no symptoms of endocrine disorder, were associated with a high concentration of substance P-like immunoreactivity. Using reverse-phase high performance liquid chromatography and antisera specifically directed against the C-terminal and N-terminal regions of substance P and against the N-terminal region of physalaemin, the following components were isolated and identified: substance P and its oxidised form, [pGlu5]substance P-(5-11) peptide and its oxidised form, and the oxidised form of physalaemin. The identity of tumour substance P with the undecapeptide was confirmed by amino acid analysis and high performance ion-exchange chromatography. In vitro incubation of tumour tissue from a lymph node metastasis from the same patient with [3H]leucine resulted in incorporation of radioactivity into newly synthesised substance P.