Insulinoma: A multicenter, retrospective analysis of three decades of experience (1983-2014)

Objective: To analyze the clinical features, diagnostic procedures, treatment, and clinical outcome of insulinomas diagnosed and treated in the period 1983-2014 in four Spanish hospitals. Methods: All patients with either biochemical and morphological criteria of insulinoma and/or histological demonstration of insulin-secreting tumor were included. Results: Twenty-nine patients [23 women (79.3%); mean age 48.7 +/- 17.4 years (range, 16-74)] were recruited. Twenty-six patients (89.7%) had sporadic tumors, and the rest (3 women, 10.3%) developed in the context of multiple endocrine neoplasia type 1. There were 3 (10.3%) multiple insulinomas, one associated with multiple endocrine neoplasia type 1, and two (6.9%) malignant insulinomas, both sporadic. Most patients (n = 18, 62.1%) had fasting hypoglycemia, about a third (31%) both postprandial and fasting hypoglycemia, and 6.9% postprandial hypoglycemia only. Time to glucose nadir (37.3 +/- 6.5 mg/dL) in the fasting test was 9.0 +/- 4.4 h, with maximal insulin levels of 25.0 +/- 20.3 mu U/mL. Abdominal CT detected insulinoma in 75% of patients. Twenty-seven (93.1%) patients underwent surgery [enucleation, 18 (66.7%) and subtotal pancreatectomy, 9 (33.3%); tumor size, 1,7 +/- 0,7 cm]. Surgery achieved cure in the majority (n = 24, 88.9%) of patients. Conclusion: In our setting, insulinoma is usually a benign, small, and solitary tumor, mainly affecting women aged 45-50 years, and usually localized with abdominal CT. The most commonly used surgical technique is enucleation, which achieves a high cure rate. (C) 2015 SEEN. Published by Elsevier Espana, S.L.U. All rights reserved.