<prompt> Most common functional neuroendocrine tumor of pancreas:GastrinomaSomatostatinomaInsulinomaVIPoma  <response>: Ans. c InsulinomaRef: Sabistons Text book of Surgery 20th Ed; Page No-952Insulinoma Insulinoma is the most common functioning pancreatic neuroendocrine tumors PNET. Incidence rate is very rare: Annually 1-2 per 1 million populations.Clinical Features Hypoglycemia including fatigue, weakness, fearfulness, hunger, tremor, diaphoresis, and tachycardia accompanied by neurologic manifestations like apathy, irritability, anxiety, confusion, excitement, loss of orientation, blurred vision, delirium, stupor, coma, or seizures It is curative because mostly benign 85-90 and solitary. The gold standard for diagnosis of insulinoma is the 72-hour monitored fast. C peptide and proinsulin values are elevated. First localization investigation performed CECT SCAN 23rd can be identified - Hypervascular lesions identified. Intraop USG is the best investigation to localize. Preoperatively-EUS has about 90 sensitivity.Treatment Head of pancreas: Enucleation is the treatment of choice.NoteEnucleation should not be performed if the tumor is within 2mm of the main pancreatic duct. Distal pancreatectomy, central pancreatectomy, or pancreaticoduodenectomy performed for tumors abutting the main pancreatic duct or for large tumors Body and tail. Diazoxide, or streptozotocin plus 5-fluorouracil used for persistent hyperinsulinism after surgery for metastatic islet cell tumors.Sabistons 20th Ed SaysHot Topic MC functioning PNET: Insulinoma Gastrinoma Second MC. MC endocrine syndrome seen in patients with MEN1: Gastrinoma 54 Insulinoma 21 Glucagonoma 3VIPoma 1. MC malignant endocrine neoplasm: Gastrinoma Insulinoma MC neuroendocrine tumor: Non-functioning tumors 