Endocrine Abstracts

Introduction

Insulinoma is the most frequent pancreatic endocrine tumor and is confirmed in case of a hyperinsulinic hypoglycemia with elevated C-peptide and absence of sulfonylureas. Tomodensitometry, MRI, endoscopic ultrasound are the imaging means used to assess localization before surgery as it is not always determined by one mean only, and in a few cases, all means may not determine localization.

Methods

This is a descriptive, retrospective study including 10 patients with confirmed insulinoma. We collected imaging results, medical treatment, surgical management and histologic finding.

Results

For the 8 patients receiving surgery, 2 didn’t have a precise localization for the tumor. Intra-operative palpation found a lesion in 3 cases, and intra-operative ultrasonography was done in 7 cases and found a lesion in 6 cases (one of them was the patient with no confirmed pre-operative localization). All 5 cases of confirmed tumor in the head of the pancreas were precisely diagnosed pre-operatively, 4 had an enucleation and one had a cephalic duodenal pancreatectomy (CDP). After enucleation, histologic examination confirmed 3 were well differenciated insulinomas and one had an islet cells hyperplasia (ICH), with a persistant hypoglycemia. The patient treated with CDP had a well differenciated tumor. The 2 cases with a suspected lesion in the tail of the pancreas and the patient with no confirmed localization had a caudal pancreatectomy (CP) with ICH in histologic finding. Medical treatment was used either for preoperative management, for post-operative control of persistant hypoglycemia or in case where surgery couldn’t be done. One patient had an inoperable malignant insulinoma, and was put on diazoxide and octreotide with a good tolerance and no hypoglycemia. One patient refused the surgery, and was put under corticosteroids with lessening of hypoglycemia. The patient with no confirmed localization had diazoxide and corticosteroids for preoperative and post-operative control with persistence of hypoglycemia. In the case of persistant hypoglycemia after enucleation, lanreotide, corticosteroids and CP were used with a good control of hypoglycemia.

Conclusion

In our serie, preoperative and intra-operative investigations were able to determine the precise localization in 7 out of 8 cases, allowing a guided surgery with a preferred enucleation if it was in the head and CP if it was in the tail. Localized tumors were definitively treated in all cases, and persistence of hypoglycemia occurred only if ICH was confirmed, a strict follow-up must then be done.