Localisation of insulinoma-single center experience

Introduction: Insulinoma is a neuroendocrine tumor derived from pancreatic β cells. Studies of clinical characteristics and therapeutic outcome of insulinoma are relatively rare because of its infrequent prevalence. The aim of this survey was to present clinical characteristics of insulinoma and to determine the success rate of different diagnostic methods in localization of insulinoma. Subjects and methods: Using hospital database we analyzed clinical course of all patients with insulinoma (N=9) who were treated at the Clinical Hospital Center Zagreb from 2010 – 2015. Results: The study group comprised 9 patients (2 men) with average age of diagnosis 49 years (range 28 to 71 years). All of them were diagnosed with insulinoma by biochemical findings of endogenous hyperinsulinemia. Average size of the tumor was 1, 69 cm. Each patient underwent surgical treatment. Two of them have a distal pancreatosplenectomy done, while other seven patents underwent an enucleation of the insulinoma. Results of diagnostic methods comparison: Abdominal ultrasound was performed in two of eight of our patients (there was no data for one patient). In both cases the result was negative. Endoscopic ultrasound was performed in six of our patients. The localization of insulinoma was confirmed in two patients and four of them had negative result. Computer tomography (CT) was performed in eight of our patients. In five of them, insulinoma was localized successfully while in three patients the result was negative. Magnetic resonance (MR) was performed in four of our patients. In all four cases, the result was positive. Selective arterial calcium stimulation was performed in six of our patients. It was positive in all cases. Conclusion: Although limited by small sample size, our results suggest that MR is the most sensitive imaging procedure for the localization of insulinoma. In the case of negative MRI, more invasive test such as selective arterial calcium stimulation is the most appropriate test.