Hypoglycemia due to an adult-onset nesidioblastosis, a diagnostic and management dilemma

We describe a case of a 40 year old patient with recurrent severe fasting and postprandial symptomatic hypoglycemia that occurred 6 years after gastric bypass surgery. The hypoglycemia was associated with increased insulin and C peptide but all diagnostic modalities for localizing an insulinoma were negative. Medical management failed to control symptoms and the patient underwent subtotal pancreatectomy. Surgical tissue examination confirmed the diagnosis of noninsulinoma pancreatogenous hypoglycaemia syndrome (NIPHS) or nesidioblastosis. Initially after surgery the patient had full remission but after 6 months hypoglycemia recurred. However, this time it was well-controlled with octreotide treatment.