The first description of carcinoid tumour was made by Lubarsch in 1888. Gastrointestinal tract [GIT] neuroendocrine tumour was first
described by Oberndorfer in 1907 as arising from enterochromaffin cells primarily in the submucosa of the intestine,accounting for 2-5%
of all malignancy and carcinoid tumour comprise the majority, 55% . It belongs to the apudomas (amine precursor uptake and
decarboxylation tumours), as it arises from endocrine amine precursor uptake and decarboxylation cells that can be found throughout the GIT
. Serotonin (5HT) was first isolated by Rapport et al.from beef serum and Erspamer showed that Kultschitsky cells secreted
5HT.It can occur in any organ derived from the primitive endoderm
but 64% originates in the GIT, with the commonest primary sites being the appendix, small intestines and rectum. In the small
intestine, majority of the cases are found in the ileum, less commonly in the jejunum and rarely involving the duodenum.
The induction of cellular proliferation by paracrine agents and growth factors is believed to follow mutations in oncogenes and tumour
suppressor genes and the amplification of HER-2/neu cellular oncogene expression has been detected in ileal carcinoids. It has been found
that stimulation of a number of the 5HT receptor subtypes, of which there are 15, has the potential to induce malignant transformation.
Last date updated on September, 2020