Gastrointestinal endocrine tumors

Jensen R. Endocrine tumors of the gastrointestinal tract and pancreas. In Jameson J, ed. Harrison s Principles of Internal Medicine, Vol. 15th ed. New York McGraw-HiU, 2001 593-603. 

TABLE 10.5 Hormonal Profiles of Gastrointestinal Endocrine Tumors ... 

Eew studies have been done on the molecular features of gastrointestinal endocrine tumors. Allelic loss of llq has been detected in GI endocrine tumors associated with MENl, and LOH of 1 Iq is also present in a subset of sporadic GI endocrine tumors. Mutations of the MENl gene are present in approximately 30% of sporadic gastrinomas and in occasional midgut and hindgut endocrine tumors. In contrast to pancreatic endocrine tumors, the CpG island methylator phenotype is frequent in GI endocrine tumors. Beta-catenin exon 3 mutations are relatively common (38%) in these tumors, and up to 80% of the tumors show nuclear and cytoplasmic localization of the corresponding protein. Other studies, however, reported absence of exon 3 mutations, but nuclear f5-catenin was found in 30% of cases. In contrast, extra-GI endocrine tumors were negative for nuclear f5-catenin. 

Viale G, Doglioni G, Gambacorta M, et al. Progesterone receptor immunoreactivity in pancreatic endocrine tumors An immunocytochemical study of 156 NE tumors of the pancreas, gastrointestinal and respiratory tracts and skin. Cancer. 1992 70 2268-2277. 

Cai YC, Banner B, Glickman J, Odze RD. Cytokeratin 7 and 20 and thyroid transcription factor-1 can help distinguish pulmonary from gastrointestinal carcinoid and pancreatic endocrine tumors. Hum Pathol. 2001 32 1087-1093. 

Srivastava A, Padilla O, Fischer-Golbrie R, et al. Neuroendocrine secretory protein-55 (NESP-55) expression discriminates pancreatic endocrine tumors and pheochromocytomas from gastrointestinal and pulmonary carcinoids. Am J Surg Pathol. 2004 28 1371-1378. 

Dayal Y, Lin HD, Tallberg K, et al. Immunocytochemical demonstration of growth hormone-releasing factor in gastrointestinal and pancreatic endocrine tumors. Am J Clin Pathol. 1986 85 13-20. 

Papotti M, Bongiovanni M, Volante M, et al. Expression of somatostatin receptor types 1-5 in 81 cases of gastrointestinal and pancreatic endocrine tumors. A correlative immunohistochemical and reverse-transcriptase polymerase chain reaction analysis. Virchows Arch. 2002 440 461-475. 

Metz DC, Jensen RT (1995) Advances in gastric antisecretory therapy in Zollinger-Ellison s)oidrome. In M Mignon, RT Jensen (eds) Endocrine tumors of the pancreas recent advances in research and management. Series Frontiers of Gastrointestinal Research. S. Karger, Basel, Switzerland, 240-257... 

Hormones transfer signals by migrating from their site of synthesis to their site of action. They are usually transported in the blood. In this case, they are said to have an endocrine effect (1 example insulin). By contrast, tissue hormones, the target cells for which are in the immediate vicinity of the glandular cells that produce them, are said to have a paracrine effect (2 example gastrointestinal tract hormones). When signal substances also pass effects back to the cells that synthesize them, they are said to have an autocrine effect (3 example prostaglandins). Autocrine effects are often found in tumor cells (see p. 400), which stimulate their own proliferation in this way. 

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