In need of glucose – case report of a rare cause of symptomatic hypoglycaemia

Abstract

Among the hypoglycemia-induced diseases we find insulinoma, insulinomatosis and also the non-insulinoma pancreatogenic hypoglycemia-syndrome (NIPHS). NIPHS is frequently caused by nesidioblastosis, which is characterized by functionally hyperactive beta cells within normal pancreatic islets. While the persistent hyperinsulinemic hypoglycemia is frequent in children, adult-onset nesidioblastosis is rare. Here we present a case of a 67-year-old female patient, who suffered from recurrent hypoglycemic episodes accompanied by cold sweats, muscle cramps, loss of consciousness, improvement of symptoms with dietary intake and weight gain. A prolonged oral glucose tolerance test with subsequent fasting revealed low- and below-normal blood glucose levels, but no disease defining hypoglycemia. Endoscopic ultrasound showed no pancreatic lesion. Ga-DOTATOC-PET/CT found 2 somatostatin receptor-positive areas in the pancreatic body and tail. By arterial calcium stimulation and venous sampling these regions showed an inappropriate insulin secretion. The clinical course until surgery was complicated by severe symptoms occurring several times a day. A therapeutic approach with acarbose and the intake of slowly absorbable carbohydrate was insufficient. Oral therapy with diazoxide was highly effective controlling the symptoms but had to be discontinued due to hypertrichosis, hypotension and edema. Thus pasireotide, a non-selective somatostatin analogue, was applied off-label achieving effective control of symptoms and blood glucose levels until surgical exploration. Finally, distal pancreatectomy was performed and pathological examination revealed adult nesidioblastosis. Postoperatively, the patient was asymptomatic without any medication or dietary interventions and lost 9 kg. The present case illustrates a rare case of adult nesidioblastosis as well as a possible targeted and pathophysiologically specific therapeutic approach with the nonselective somatostatin analogue pasireotide.