Insulinoma: diagnostic features and treatment management

Abstract

Background. Insulinoma is the most common functional pancreatic neuroendocrine tumor originating from β-cells, with unregulated insulin production and rarely associated with MEN-I syndrome. Diagnosis and treatment of insulinoma are a challenge in the practice of endocrinologist.
 Aim. To determine on the basis of retrospective analysis the optimal approaches to the management of patients with organic hyperinsulinism.
 Material and methods. Medical records of 72 patients admitted with suspected organic hyperinsulinism had been screened and medical histories of patients with a confirmed diagnosis of organic hyperinsulinism were included into the analysis. Anamnesis, results of objective, laboratory and instrumental examinations, methods and results of the treatment were analyzed.
 Results. The diagnosis of insulinoma was confirmed in thirty two cases. Hypoglycemia was achieved within the first 48 hours after the start of the 72-hour fasting test in 100% of cases. Study results showed that in 50% of cases the size of the pancreatic neoplasm was more than 1.4 cm. Inverse correlation between tumor size and plasma glucose concentration at the time of hypoglycemia was found (r=–0.45; р=0.02). Surgical treatment was carried out in thirty out of 32 patients. Surgical enucleation of insulinoma was performed in 12 (40%) cases, distal pancreatectomy — in 18 (60%). Insulinoma was confirmed in 27 cases, while in three patients diagnosis of non-insulinoma pancreatogenous hypoglycemia («nesidioblastosis») was established according to histological findings. Positive clinical result was achieved after all surgeries. In postoperative period patients were discharged within 11—30 days. Patients without post-operative complications were discharged 13.0±1.4 days after surgery. Twelve (40%) patients developed post-operative complications. The duration of hospital stay in these cases was significantly longer 20.1±1.9 (р<0,01).
 Conclusion. Obtained data confirmed that comprehensive approach including 72-hours fasting test, use of modern imaging techniques and application of high-tech treatment methods, is crucial for successful diagnosis and treatment of insulinoma.