Are there treatment guidelines for insulinoma?

Yes: First is appropriate diagnosis. Make sure that the patient's blood sugar is repaetedly low and that they are not taking Insulin or other drugs. Next, scans may be useful for localizing the tumor. Only then - an experienced endocrine (or hepatopancreatobiliary) surgeon should remove it. These tumors are very rare, often hard to find, and you should go to a specialized center for surgery.

Yes: The north american neuroendocrine tumor society (nanets) provides guidelines at http://nanets.Net/research/articles/nanets-guidelines. The national comprehensive cancer network (nccn) also provides guidelines. These should be treated by a multidisciplinary team including a pancreatic surgeon.