<prompt> In Carcinoma head of pancreas, Nausea vomiting is due to:External Compression of duodenumPortal vein infiltrationProliferation infiltration of tumor into duodenumChemotherapy related  <response>: Ans. a External Compression of duodenumRef: Blumgarts 6th ed; pg. 979; Sabiston 20th ed; pg. 1544 Pancreatic adenocarcinoma develops in the ductal cells and are called Ductal Adenocarcinoma. They most commonly occur on the Right side, i.e., Head and Uncinate Process 60-70 than left side, i.e., Body and Tail of pancreas 20-25 Features of Carcinoma Head of Pancreas are Jaundice 75 Weight loss 51 Abdominal pain 39 Nauseavomiting 13 Pruritus 11 Fever 3 Gastrointestinal bleeding 1 For tumors at the body and tail of pancreas, Pain most common and weight loss are the presenting features as they present at a late advanced stage Regarding Nausea and vomiting, they occur due to tumor extrinsic compression of duodenum C loop presenting a state of Gastric outlet obstruction. In unresectable cases, these patients should be offered Endoluminal duodenal metal stent as palliation. 