No special group is susceptible, but it is often found in those afflicted by the familial complex of tumors known as MEN (multiple endocrine neoplasia) type-I, a genetically transmitted group of endocrine abnormalities. These people develop several kinds of islet cell tumors—54 percent have multiple gastrinomas, 21 percent develop insulinomas, 3 percent glucagonomas and 1 percent VIPomas. They also have a tendency to develop pituitary, parathyroid and adrenal gland tumors.
