Malignant insulinoma misdiagnosed and treated as epilepsy

Pancreatic neuroendocrine tumors (PNET) are extremely rare, and although insulinomas are the commonest, less than 10% of insulinomas are malignant. Most patients with insulinomas present neuroglycopenic symptoms. Because of the rarity of the condition, we report the case of a 56-year-old man with malignant insulinoma, which was misdiagnosed as epilepsy. Timely diagnosis of this disease is of paramount importance to prevent neurologic sequelae of hypoglycemia. Insulinomas should be regarded from the beginning as potentially malignant, although the majority of malignant insulinomas progresses slowly.