title: Insulinoma or non-insulinoma pancreatogenous hypoglycemia? A diagnostic dilemma.
abstract: Insulinoma is the most common cause of endogenous hyperinsulinemic hypoglycemia in adults. An alternate etiology, non-insulinoma pancreatogenous hypoglycemia (NIPH), is rare. Clinically, NIPH is characterized by postprandial hyperinsulinemic hypoglycemia, negative 72-h fasts, negative preoperative localization studies for insulinoma and positive selective arterial calcium infusion tests. Histologically, diffuse islet hyperplasia with increased number and size of islet cells is present and confirms the diagnosis. Differentiating NIPH from occult insulinoma preoperatively is challenging. Partial pancreatectomy is the procedure of choice; however, recurrence of symptoms, although less debilitating, occurs commonly. Medical management with diazoxide, verapamil and octreotide can be used for persistent symptoms. Ultimately, near-total or total pancreatectomy may be necessary. We report a case of a 67-year-old male with hypoglycemia in whom preoperative workup, including computerized tomography abdomen, suggested insulinoma, but whose final diagnosis on pathology was NIPH instead.
authors.affiliation: Department of Surgery, University of Alberta, Edmonton, Canada.
authors.forename: Blaire
authors.initials: B
authors.lastname: Anderson
authors.affiliation: Department of Surgery, University of Alberta, Edmonton, Canada.
authors.forename: Jordan
authors.initials: J
authors.lastname: Nostedt
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada.
authors.forename: Safwat
authors.initials: S
authors.lastname: Girgis
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada.
authors.forename: Tara
authors.initials: T
authors.lastname: Dixon
authors.affiliation: Department of Medicine, Division of Endocrinology and Metabolism, University of Alberta, Edmonton, Canada.
authors.forename: Veena
authors.initials: V
authors.lastname: Agrawal
authors.affiliation: Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Canada.
authors.forename: Edward
authors.initials: E
authors.lastname: Wiebe
authors.affiliation: Department of Medicine, Division of Endocrinology and Metabolism, University of Alberta, Edmonton, Canada.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Senior
authors.affiliation: Department of Surgery, University of Alberta, Edmonton, Canada amjs@islet.ca.|Department of Medicine, Division of Endocrinology and Metabolism, University of Alberta, Edmonton, Canada.
authors.forename: A M James
authors.initials: AM
authors.lastname: Shapiro