Occult Abdominal Para-Aortic Ectopic Insulinoma Localized by 18F-NOTA-Exendin-4 PET/CT

Solitary ectopic insulinomas without concurrent pancreatic or gastrointestinal lesions are exceedingly rare. We report the ¹⁸ F-NOTA-exendin-4 PET/CT findings of a solitary ectopic insulinoma in a 68-year-old woman with a 10-year history of recurrent hypoglycemic syncope. Endogenous hyperinsulinemia was confirmed, but conventional imaging and laparoscopic pancreatic exploration were negative. PET/CT revealed a solitary intense focus in the para-abdominal aortic region. Surgical resection confirmed a solitary ectopic insulinoma, and postoperative hypoglycemia resolved. This case highlights the value of ¹⁸ F-NOTA-exendin-4 PET/CT in identifying occult solitary ectopic insulinomas when conventional imaging and surgical exploration are unrevealing, enabling curative resection.