Endocrine Abstracts

Insulinoma is a very rare type of islet cell tumor. The aim of our study is to report our clinical experience with insulinoma in order to determine clinical, biological, radiological and therapeutic particularities of this tumor type.

It’s a retrospective study, including five patients (three women and two men) referred to our department between 2005 and 2011 for hypoglycemia exploration. Mean age of our group is 39.8±15.4 years (ranges: 20–60 years). Two women were type 2 diabetic patients.

All our patients showed neuroglycopenic symptoms associated with a blood glucose level <0.5 g/l. Three patients had a weight gain of 16±13.5 kg (ranges: 3–30 kg).

The fasting test was interrupted after 6.6±4 h (ranges: 3–11 h), showing an inadequate high insulin (ranges: 4.2–240.5 UI/ml) and C-peptide (ranges: 2.91–14.4 ng/ml) secretion with hypoglycemia (ranges: 1.5–2 mmol/l). The screening for sulfonylurea was negative in all patients confirming the diagnosis of insulinoma. It was a sporadic form of insulinoma in all patients.

Endoscopic ultrasonography and CT-scan showed a tail pancreatic tumor measuring 17 mm in one case, and were negative in the other cases. In this group, the tumor was detected using per-operative ultrasonography. All our patients underwent enucleation without any per or post-operative complications. Postoperative glucose metabolism was normalized in all patients even in diabetic patients.

The combination of hypoglycemia and endogenous hyperinsulinemia with a negative screening for sulfonylurea confirm the diagnosis of insulinoma. However, preoperative localization techniques can be negative especially in very small tumor. In this case, Intraoperative ultrasonography is helpful.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.