Gastrointestinal tract carcinoid tumor

Shebani KO, Souba WW, Finkelstein DM, et al. (1999) Prognosis and survival in patients with gastrointestinal tract carcinoid tumors. Ann Surg 229 815-21... 

C. Carcinoid tumors arise from neuroendocrine cells of the gut and secrete serotonin and gastrointestinal hormones, which activate the gastrointestinal tract and result in diarrhea. Most of these tumors have receptors for somatostatin, which inhibit secretion when activated, resulting in reduced activity of the gut. Octreotide is a stable analogue of... 

The positive staining for AE1/AE3 and CAMS.2 that is seen in gastric carcinoids can help distinguish them from secondary involvement of the gastrointestinal tract by other neuroendocrine tumors such as pheochromocytoma and retroperitoneal paraganglioma. 

For practical purposes, a serotonin-producing tumor should be regarded as a carcinoid, and if it is in the pancreas, the possibility of metastasis from the gastrointestinal tract or elsewhere should be ruled out. 

Carcinoid tumors arising from the argentaffin cells of the gastrointestinal (GI) tract secrete excessive amounts of serotonin, the local action of which in the gut provokes diarrhoea. Measurement of serotonin or 5-HIAA is useful in the detection of carcinoid tumors and in monitoring therapy. 

In 1930, F. Feyrter (top left) of Gdansk proposed the existence of a diffuse system of neuroendocrine cells in the gastrointestinal tract (center). Thereafter, P. Masson (1880-1959) (bottom right) described in detail the characteristics of the cells that formed the basis of the diffuse neuroendocrine system (back-ground). In addition, Masson proposed that the enterochromaffin cells in the crypts of Lieberkuhn (which had been identified by N. Kulchitsky in 1897) were the progenitors of neuroendocrine tumors of the gut (carcinoids). 

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