Islet cell tumors of the pancreas.

Islet cell tumors of the pancreas are present in 65% to 80% of patients with MEN 1 syndrome. The tumors are typically multifocal and may secrete multiple peptides either concurrently or at different times in the course of a patient's disease. Gastrinomas are most common and present the Zollinger-Ellison syndrome. Although curative surgery is possible in some cases, medical therapy is quite effective in most. Hypoglycemia due to insulin-secreting tumor is amenable to curative surgery in many cases. With prospective family screening programs and improved diagnostic techniques the disease is being diagnosed at an early, often preclinical stage in recent years.