Ectopic insulinoma diagnosed by 68Ga-Exendin-4 PET/CT: A case report and review of literature

Medicine (Baltimore). 2021 Apr 2;100(13):e25076. doi: 10.1097/MD.0000000000025076.

Abstract

Rationale: Ectopic insulinomas are extremely rare and challenging to diagnose for clinicians. Precise preoperative localization is essential to successful treatment.

Patient concerns: A 23-year-old man presented with a 1-year history of recurrent hypoglycemia.

Diagnosis: Examinations in the local hospital did not reveal any pancreatic lesion. After admission, a fasting test and a 5-hour oral glucose tolerance test (OGTT) suggested a diagnosis of endogenous hyperinsulinemic hypoglycemia. Enhanced volume perfusion computed tomography (VPCT) revealed 2 nodules in the tail of the pancreas, a nodule in the gastric antrum, and a nodule in the hilum of the spleen. To differentiate which nodule was responsible for hypoglycemia, we performed 68Ga-Exendin-4 PET/CT and 68Ga-DOTATATE PET/CT which helped to make a conclusive diagnosis that the lesion in the gastric antrum was an ectopic insulinoma.

Interventions: The patient was cured with minimally invasive laparoscopic resection of the tumor.

Outcomes: The symptoms were relieved and the blood glucose level remained normal after surgery.

Conclusions: This case shows that 68Gallium-exendin-4 PET/CT is useful for precise localization and thereby successful treatment of insulinoma, especially for occult insulinomas and those derived from an ectopic pancreas.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Choristoma / complications
  • Choristoma / diagnostic imaging*
  • Exenatide
  • Gallium Radioisotopes
  • Glucose Tolerance Test
  • Humans
  • Hypoglycemia / diagnostic imaging
  • Hypoglycemia / etiology
  • Insulinoma / complications
  • Insulinoma / diagnostic imaging*
  • Male
  • Organometallic Compounds
  • Pancreas
  • Pancreatic Neoplasms / diagnostic imaging*
  • Positron Emission Tomography Computed Tomography*
  • Pyloric Antrum / diagnostic imaging
  • Radiopharmaceuticals
  • Recurrence
  • Stomach Neoplasms / diagnostic imaging*
  • Young Adult

Substances

  • Gallium Radioisotopes
  • Organometallic Compounds
  • Radiopharmaceuticals
  • Gallium-68
  • gallium Ga 68 dotatate
  • Exenatide