Tumors of the islets of Langerhans.

The islet cell tumors of the pancreas are now known to produce a variety of polypeptides in addition to insulin. These include glucagon, serotonin, corticotropin, melanocyte-stimulating hormone, gastrin and a secretinlike hormone that may be VIP or a combination of such polypeptides. The development and wide availability of the newer immunoassays for the various recognized hormones as well as candidate hormones of the gut will simplify the diagnosis of these challenging tumors, which up until this time have produced symptoms that were bizarre and often fatal to the patient.