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

Hypothesis: Nesidioblastosis is an important cause of adult hyperinsulinemic hypoglycemia, and control of this disorder can often be obtained with a 70% distal pancreatectomy. Design: The records of all adult patients operated on for hypoglycemia between 1974 and 1999 were reviewed retrospectively. Patients with the pathologic 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 literature. Setting: The University of Chicago Medical Center (Chicago, ill), a tertiary 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 medication, development of insulin-dependent diabetes mellitus, pancreatic exocrine insufficiency, and need for reoperation. Results: Of 32 adult patients who underwent surgical exploration for hyperinsulinemic hypoglycemia at our institution, 27 (84%) were found to have 1 or 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 patients (60%) asymptomatic and taking no medications, and 2 patients (40%) experiencing some recurrences of hypoglycemia. The 2 patients with recurrences are 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 study indicates that a 70% distal pancreatectomy is often successful in controlling hypoglycemia, and rarely results in diabetes mellitus. However, the optimal treatment of this disorder remains to be determined.