A rare but highly treatable type of pancreatic cancer that begins in the cells of the pancreas that produce insulin and other hormones. Islet cell cancer can cause the pancreas to produce too much insulin or other hormones. When this happens, the patient may feel weak or dizzy and may have chills, muscle spasms, and diarrhea as well as pain in the stomach or abdomen. Islet cell cancer is also called islet cell carcinoma. See the entire definition of Islet cell cancer