A Clinical Case of Insulinoma Presenting with Postprandial Hypoglycemia in a Patient with a History of Gastric Bypass Surgery

Intern Med. 2022 Apr 15;61(8):1189-1195. doi: 10.2169/internalmedicine.7428-21. Epub 2021 Oct 12.

Abstract

A 61-year-old man with a history of total gastrectomy for cancer with Roux-en-Y reconstruction showed severe postprandial hypoglycemia accompanied by endogenous hyperinsulinemia. Abdominal ultrasonography and contrast-enhanced computed tomography showed no abnormal findings in the pancreas. A selective arterial secretagogue injection test showed the marked induction of serum immunoreactive insulin when calcium was injected into the splenic artery. A pathological analysis following distal pancreatectomy with splenectomy revealed a pancreatic neuroendocrine microadenoma containing insulin-producing cells in the resected pancreas. This case highlights the importance of carefully evaluating refractory and severe hypoglycemia in patients with a history of gastric surgery to exclude insulinoma.

Keywords: hypoglycemia; insulinoma.

Publication types

  • Case Reports

MeSH terms

  • Gastric Bypass* / adverse effects
  • Humans
  • Hypoglycemia* / etiology
  • Insulin
  • Insulinoma* / complications
  • Insulinoma* / diagnosis
  • Insulinoma* / surgery
  • Male
  • Middle Aged
  • Pancreatectomy / methods
  • Pancreatic Neoplasms* / complications
  • Pancreatic Neoplasms* / surgery

Substances

  • Insulin