Carcinoid tumor secretes

Ans. c (5 HT). (Ref. Baily & Love, Surgery, 22nd/pg.800)CARCINOID TUMOR# Arises from argentaffin/chromafin cells, called as Kulschitsky cells.# These cells stain with ammoniacal silver salt solution to black.# Most common site of occurence is appendix and is benign there.# Next common site is ileum and most of them are malignant.# More than 9 mg/ 24-hour of 5-HIAA in 24 in urine is diagnostic. Carcinoid also secretes 5-HT.# Carcinoid syndrome is characterized by attacks of flushing and diarrhoea, abdominal cramps, bronchospasm, tricuspid and pulmonary regurgitation/stenosis and telangectasia.# Most common cause is small bowel carcinoid metastasizing to liver; and next common is bronchial carcinoid.# Cardiac changes in carcinoid heart disease are largely right sided (tricuspid valve) and are due to inactivation of both serotonin and bradykinin in the blood during passage through lungs by monoamino-oxidase present in pulmonary vascular endothelium.