Which of the following is true of small bowel carcinoids

Ans. is 'none' Lets see each option one by one Most common site: Most common site for small bowel carcinoids is ileum. About 70-87% are present within the ileum and 40-70% are within 2 ft of the ileocecal valve. Among all carcinoids most common site is GI tract 2nd most common site is respiratory tract Endocardial fibroelastosis is cardiac manifestation of carcinoid syndrome, produced due to biologically active substances (mainly serotonin) secreted by carcinoids. Endocardial fibroelastosis is fibrous involvement of the endocardium, primarily the right side of the hea. No increased risk of Ca lung is noted. Previously small cell Ca of lung and carcinoid tumors were thought to be similar representing the spectrum of neuroendocrine tumors of the lung. Recent studies using gene expression profiles have proved them to be dissimilar. Small cell lung cancers are derived from bronchial epithelium & carcinoids are derived from neural crest Carcinoid tumor location, Frequency of Metastases, and Association with the Carcinoid Syndrome Location (% of Total) Incidence of Metastases Incidence of I Carcinoid 1 Syndrome Foregut Esophagus <0.1 - ? Stomach 4.6 10 9.5 Duodenum 2.0 3.4 Pancreas 0.7 71.9 20 Gallbladder 0.3 17.8 5 Bronchus, lung, trachea 27.9 5.7 13 Midgut Jejunum 1.8 1 58.4 9 Ileum 14.9 r 9 Meckel's diveiculum 0.5 13 Appendix 4.8 38.8 <1 Colon 8.6 51 5 Liver 0.4 32.2 ? Ovary 1.0 32 50 Testis <0.1 - 50 Hindgut Rectum 13.6 3.9 -