A Long Way to Find a Small Tumor: The Hunt for an Insulinoma

We report a case of a 35-year-old woman with recurrent episodes of hypoglycemia. Biochemical investigation was suggestive of hyperinsulinemic hypoglycemia, and hence a provisional diagnosis of insulinoma was made. Despite extensive investigation using magnetic resonance imaging, endoscopic ultrasound, and ⁶⁸Ga-DOTATATE positron emission tomography/computed tomography (PET/CT) scanning, the tumor could not be localized. Long-distance travel allowed her to undergo a ⁶⁸Ga-Exendin-4 PET/CT scan that identified a lesion in the uncinate process of the pancreas, subsequently confirmed by intraoperative ultrasound. Enucleation of the 1.5-cm lesion was performed, and histopathology confirmed a well-differentiated pancreatic neuroendocrine tumor. Postoperatively, the patient has remained free of hypoglycemic episodes and has shown normalization of glucose levels. This case underscores the efficacy of ⁶⁸Ga-Exendin-4 PET/CT in the localization of an occult insulinoma, facilitating timely and curative surgical intervention, and the importance of patients having access to such a facility when not locally available.