Published online Apr 14, 2015. doi: 10.3748/wjg.v21.i14.4413
Peer-review started: November 5, 2014
First decision: December 11, 2014
Revised: December 25, 2014
Accepted: January 21, 2015
Article in press: January 21, 2015
Published online: April 14, 2015
Ectopic insulinoma is a very rare and dormant tumor. Here we report the case of a 79-year-old female who presented with repeated episodes of hypoglycemia and was diagnosed with insulinoma based on laboratory and imaging examinations. Computed tomography and positron emission tomography revealed a tumor in the retroperitoneum under and left of the hepatoduodenal ligament, which was resected successfully using a laparoscopic approach. Pathologic results revealed an ectopic insulinoma, which was confirmed immunohistochemically. Ectopic insulinomas are accompanied by hypoglycemia that can be misdiagnosed as drug- or disease-induced. These tumors are difficult to diagnose and locate, particularly in atypical cases or for very small tumors. Synthetic or targeted examinations, including low blood glucose, elevated insulin, proinsulin, and C-peptide levels, 48-h fasting tests, and relevant imaging methods should be considered for suspected cases of insulinoma. Surgery is the treatment of choice for patients with insulinoma, and laparoscopic resection is a feasible and effective method for select ectopic insulinoma cases.
Core tip: Ectopic insulinoma is a very rare and dormant disease that is difficult to diagnose and locate. It should be considered in the differential diagnosis of cases of hypoglycemia thought to be caused by drugs and other diseases. Correlative laboratory and imaging examinations are necessary, and laparoscopic resection is a feasible and effective treatment approach.