I. EXTRAPANCREATIC ISLET ADENOMA AS A CAUSE OF HYPERINSULINISM AND HYPOGLYCEMIA Masses of aberrant pancreatic tissue varying greatly in size have been described by many authors since Klob's1 first report in 1859. Faust and Mudgett2 in 1940 recorded the locations of such aberrant tissue in 370 published cases (table) as follows: No. of Cases No. of Cases Exceedingly variable symptoms are attributable to aberrant pancreatic tissue. These symptoms may be indistinguishable from those due to simple ulcer, such as anorexia, nausea, vomiting, epigastric pain, insomnia and loss of weight. Symptoms not unlike those due to appendicitis, cholecystitis or diverticulitis have been described in association with or directly attributable to this extrapancreatic tissue. Symptoms of obstruction due to intussusception have been precipitated by abnormally placed pancreatic tissue within the lumen of the bowel. Insidiously progressive digestive disturbances together with debility and loss of weight have suggested the presence of cancer of some intra-abdominal organ.