Objectives: Insulinomas are rare tumours that originate from the islet cells of the pancreas. The aims of this study were to gain an understanding of the clinical features of insulinomas and to establish the diagnostic and therapeutic strategies.
Methods: A review was carried out in 20 patients with insulinoma surgically treated in our institution over the last 10 years. Presenting symptoms, biochemical studies, preoperative and intraoperative localization studies, operative management and complications were analysed.
Results: The male-to-female ratio was 8:12, with a mean age of 46.4 years. Each patient suffered from significant neuroglycopenic symptoms, usually manifested by dizziness, sweating, headache and confusion. The preoperative median serum levels of glucose, insulin and C-peptide at the termination of the fast were 37.5 mg/dL, 23.5 microU/mL, 5.6 ng/mL, respectively. Preoperative tumour localization was achieved by means of ultrasonography (US), computed tomography, selective angiography or intra-arterial calcium injection with hepatic venous sampling, and sensitivities of these examinations were 81.8, 73.7, 94.1 and 100%, respectively. Intraoperative localization was carried out by a combination of manual palpation and intraoperative US with retrospective sensitivities of 80 and 100%, respectively. Enucleation was carried out in 16 patients and distal pancreatectomy in 4. The mortality and morbidity rates were 0 and 10%, respectively. One patient developed late diabetes mellitus type 1 after distal pancreatectomy.
Conclusions: We conclude that the diagnosis of insulinoma can be made on the basis of the results of a supervised fast, careful palpation with intraoperative US is essential for intraoperative detection of insulinomas and surgical resection is the best choice for treatment of benign insulinomas.