Gastrointestinal Neuroendocrine Tumors and the Carcinoid Syndrome

In: Endotext [Internet]. South Dartmouth (MA):, Inc.; 2000.


Neuroendocrine neoplasms originating from the gut are increasingly diagnosed as a result of the rise in radiological and endoscopic procedures, improved pathological classification, and likely an increase in true incidence. The diffuse neuroendocrine gastrointestinal system can trigger cancer formation into a wide variety of neoplasm subtypes, ranging from well-differentiated tumors to poorly differentiated carcinomas. All gastrointestinal neuroendocrine neoplasms have the potential to metastasize and ultimately impair patient survival. In recent years, changes have occurred in the pathophysiological understanding, nomenclature, pathological grading, molecular imaging, and management options for these neuroendocrine neoplasms. This chapter will focus on well-differentiated neuroendocrine tumors of gastrointestinal origin, which find their origin at separate primary locations, all characterized by their specific clinical behavior. A minority of patients suffer from hormonal syndromes due to the secretion of peptides or amines from the neuroendocrine tumor. The carcinoid syndrome is the quintessential hormonal syndrome in gastrointestinal neuroendocrine tumors, particularly those of midgut origin. Patients suffering from the carcinoid syndrome have a reduced survival and quality of life, due to debilitating symptoms of flushing and diarrhea as well as fibrotic complications. We provide an overview of the background of gastrointestinal neuroendocrine tumors as well as the carcinoid syndrome and discuss the diagnostic pathways as well as treatment possibilities for patients presenting with this disease. For complete coverage of all related areas of Endocrinology, please visit our on-line FREE web-text, WWW.ENDOTEXT.ORG.

Publication types

  • Review