Surgical outcomes in patients with resected insulinoma

Abstract

Background: Insulinomas are rare functional pancreatic neuroendocrine tumors. In this large single-institution retrospective series we assess the surgical outcomes of resected insulinoma cases. Methods: The institutional pathology database was utilized for identification of all resected insulinoma cases within the last 10 years. Clinicopathological information and follow-up data were collected and assessed for postoperative patient outcomes. Results: In the studied period, 40 patients with resected insulinoma were identified; they were predominantly white (80%) and female (65%), with a median age of 50 years (IQR 38-58). All patients presented with Whipple’s triad (symptomatic hypoglycemia, blood glucose level <50 mg/dL, and symptom relief with glucose administration), accompanied occasionally by weight gain (n = 18, 45%), personality changes (n = 33, 82.5%), or syncopal episodes (n = 18, 45%). In four cases (10%) the lesion was associated with MEN-1 syndrome and the rest were sporadic. Endoscopic ultrasound was the main diagnostic tool for tumor localization; lesion enucleation was performed for smaller lesions in 25% of the patients. The median tumor size was 13 mm (IQR 10-21), and most lesions were unifocal (n = 34, 85%) and located in the distal pancreas (n = 23, 57.5%). One patient (2.5%) had a distant liver metastasis at diagnosis that was also resected; he underwent a second liver resection for recurrence 3 years later and the patient is alive 9 years after initial presentation. Insulinoma recurrence was also identified locally in a patient with a previous R1 resection 2 years later (2.5%). Median patient follow-up was 16 months (IQR 4-57) and disease-associated mortality was zero. Conclusion: Insulinomas are rare pancreatic neuroendocrine tumors with favorable biology. Surgical resection is the treatment of choice with excellent prognosis.