Small Intestine MCQs

A majority of pancreatic enzymes are synthesized as inactive pro-enzymes and sequestered in membrane bound zymogen granules, as mentioned earlier. Activation of pro-enzymes requires conversion of trypsinogen to trypsin by duodenal entero peptidase. Reference: Robbins Basic Pathology, 10 th edition, Pg-679

Carcinoid tumors are malignant tumors composed of cells that contain dense-core neurosecretory granules in their cytoplasm and, rarely, may secrete hormonally active polypeptides. These are rare, slow growing neuroendocrine tumours arising from the enterochromaffin cells. Reference: Robbins Basic Pathology, 10 th ed, Pg-543-44

Answer is D (5HIAA): Carcinoid Tumors Carcinoid tumors are associated with elevated levels of metabolites of Tryptophan/ serotonin which include 5HIAA, 5HT and5HTP. Pheochromocytomas Pheochromocytomas are associated with elevated levels of catecholamines and their metabolites which include Vanillylmandelic acid (VMA)and metanephrines The diagnosis of Typical carcinoid syndrome is suggested by elevated levels of 5HIAA The diagnosis of Atypical Carcinoid Syndrome is suggested by elevated levels of 5HTP. established by elevated levels of 5HIAA.