Adult Nesidioblastosis in Chronic Kidney Disease

CONTEXT: Nesidioblastosis is a rare cause of hyperinsulinemic hypoglycemia in adults. The diagnosis is further complicated in patients with kidney failure, since impaired renal function can cause hypoglycemia by itself and diagnostic criteria for this clinical scenario have not been developed yet. CASE DESCRIPTION: We present the case report of a 36-year-old patient with end stage chronic kidney disease who presented to the emergency department because of hypoglycemia. However, the patient's hypoglycemia did not respond well to medical treatment; the diagnosis of hyperinsulinemic hypoglycemia was made due to the presence of inappropriately high levels of insulin, proinsulin, and C-peptide during an episode of hypoglycemia. Imaging studies were performed without any conclusive findings; so selective intra-arterial pancreatic stimulation with hepatic venous sampling (SACTS) was done. Based on the results of this study the patient was referred for subtotal pancreatectomy. Classic criteria for the diagnosis of insulinoma with SACTS required a 2-fold increase in insulin levels but newer criteria suggest thresholds that are useful in the differential diagnosis of insulinoma and nesidioblastosis. In our patient, the former criteria were positive; however, the new criteria were not compatible with insulinoma but with nesidioblastosis, which was the final histopathological diagnosis. CONCLUSION: This seems to be the first case report of a patient with end stage chronic kidney disease and nesidioblastosis, as well as the first case of hyperinsulinemic hypoglycemia in the context of kidney failure diagnosed by SACTS. We consider this method to be very useful in patients with renal impairment because peripancreatic insulin levels do not depend on the renal function.