Insulinoma after Roux-en-Y gastric bypass successfully treated by endoscopic ultrasound-guided radiofrequency...

Post-bariatric hypoglycemia (PBH) can significantly impact patient quality of life and is generally referred to as postprandial hyperinsulinemic hypoglycemia or late dumping. In this report, we present the case of a 55-year-old man with a recent history of Roux-en-Y gastric bypass (RYGB) surgery and multiple admissions owing to hypoglycemic coma postoperatively. Initially, the hypoglycemic episodes were interpreted as being caused by PBH. Due to symptom severity, a fasting test was performed, revealing hypoglycemia and inappropriate hyperinsulinemia, suggestive of an insulinoma. Further computed tomography evaluation revealed a lesion in the pancreatic neck, which could not be demonstrated on gallium-68 (⁶⁸Ga)-labeled dodecanetetraacetic acid-tyrosine-3-octreotate (DOTATATE) positron emission tomography-computed tomography (PET-CT). Anatomopathological confirmation was pursued using endoscopic ultrasound (EUS)-guided fine needle aspiration through EUS-directed gastrogastrostomy and showed presence of a grade 1 neuroendocrine tumor. We decided to perform EUS-guided radiofrequency ablation (RFA), which resulted in complete resolution of the hypoglycemic episodes. This case report offers an important contribution by demonstrating successful treatment of an insulinoma by RFA via an EUS-guided gastrogastrostomy approach after RYGB, which has not been previously well established. It also underlines the importance of considering alternative causes of recurrent hypoglycemia after bariatric surgery beyond PBH.