Adult-onset nesidioblastosis: a challenging diagnosis revealed by glucagon-like-peptide-1 receptor imaging

Abstract

A 52-year-old female presented with recurrent episodes of fasting or post-absorptive hypoglycemia. A 72-h fasting test confirmed endogenous hyperinsulinemia. Conventional imaging was unremarkable. Selective pancreatic arterial calcium stimulation and hepatic venous sampling showed a maximum calcium-stimulated insulin concentration from several pancreatic areas, mainly the proximal splenic artery and the proximal gastroduodenal artery, suggesting the presence of one or more occult insulinoma(s) in the region of the pancreatic body.68Ga-DOTA-exendin-4 PET/CT showed however generalized increased uptake in the pancreas and a diagnosis of nesidioblastosis was therefore suspected. The patient has been since successfully treated with dietetic measures and diazoxide. Treatment efficacy was confirmed by a flash glucose monitoring system with a follow-up of 7 months.