Which of the following is the most common 5081. functioning pancreatic islet cell tumour ?

Gastroenteropancreatic NETs arise in organs that are derived embryologically from the gastrointestinal tract. Most commonly, they occur in the small bowel but they can also arise elsewhere in the bowel, pancreas, thymus and bronchi. The term 'carcinoid' is often used when referring to non-pancreatic gastroenteropancreatic NETs because, when initially described, they were thought to behave in an indolent fashion compared with conventional cancers. It is now recognised that there is a wide spectrum of malignant potential for all NETs; some are benign (most insulinomas and appendiceal carcinoid tumours), while others have an aggressive clinical course with widespread metastases (small-cell carcinoma of the lung). The majority of gastroenteropancreatic NETs behave in an intermediate manner, with relatively slow growth but a propensity to invade and metastasise to remote organs, especially the liver Ref Harrison 20th edition pg 517