Adult-onset nesidioblastosis causing hypoglycemia - An important clinical entity and continuing treatment dilemma

Hypothesis: Nesidioblastosis is an important cause of adult hyperinsulinemi c hypoglycemia, and control of this disorder can often be obtained with a 7 0% distal pancreatectomy. Design: The records of all adult patients operated on for hypoglycemia betw een 1974 and 1999 were reviewed retrospectively. Patients with the patholog ic diagnosis of nesidioblastosis were contacted for follow-up (1.5-21 years ) and are presented. Patients' results were compared with those of 36 other individuals with this disorder who were previously reported in the literat ure. Setting: The University of Chicago Medical Center (Chicago, ill), a tertiar y care facility. Patients: A consecutive sample of all patients operated on for hypoglycemia . Interventions: Seventy percent distal pancreatectomy for all patients with nesidioblastosis, and maintenance therapy with verapamil hydrochloride for 2 patients. Main Outcome Measures: Achievement of normoglycemia with and without medica tion, development of insulin-dependent diabetes mellitus, pancreatic exocri ne insufficiency, and need for reoperation. Results: Of 32 adult patients who underwent surgical exploration for hyperi nsulinemic hypoglycemia at our institution, 27 (84%) were found to have 1 o r more insulinomas, and 5 (16%) were diagnosed with nesidioblastosis. Each patient with nesidioblastosis underwent a 70% distal pancreatectomy. Follow -up duration for the 5 patients ranged from 1.5 to 21 years, with 3 patient s (60%) asymptomatic and taking no medications, and 2 patients (40%) experi encing some recurrences of hypoglycemia. The 2 patients with recurrences ar e now successfully treated with a calcium channel blocker, an approach, to our knowledge, never before reported for adult-onset nesidioblastosis. Conclusions: Nesidioblastosis is an uncommon but clinically important cause of hypoglycemia in the adult population, and must always be considered in a patient with a presumptive preoperative diagnosis of insulinoma. This stu dy indicates that a 70% distal pancreatectomy is often successful in contro lling hypoglycemia, and rarely results in diabetes mellitus. However, the o ptimal treatment of this disorder remains to be determined.