You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Most common site for carcinoid tumor and explain in detail?
Carcinoid tumour arise from the enterochromaffin cells (Kulchitsky cells) found in the crypts of Lieberkuhn. These cells are capable of APUD (Amine precursor uptake and Decarboxylation) and can secrete vasoactive amines like 5- HT, 5-HIAA, 5-HTP; tachykinins, peptides (chromogranins)and PGs. It commonly occurs in appendix (45%), ileum (25%) and rectum (15%). Other (15%) sites are--other pas of GIT (including pancreas and biliary tract), bronchus and testis.Reference: page 877 SRB's manual of surgery 5th edition