Objective: To analyze the characteristics and outcomes following enucleation and pancreatic resections of insulinomas.
Design: Retrospective cohort study; prospective database.
Settings: Academic, tertiary, and referral centers.
Patients: Consecutive patients with insulinomas (symptoms of hyperinsulinism and positive fasting glucose test) who underwent surgical treatment between January 1990 and December 2009.
Main outcome measures: Operative morbidity, tumor recurrence, and survival after treatment.
Results: A total of 198 patients (58.5% women; median age, 48 years) were identified. There were 175 (88%) neuroendocrine tumors grade G1 and 23 (12%) neuroendocrine tumors grade G2. Malignant insulinomas defined by lymph node/liver metastases were found in 7 patients (3.5%). Multiple insulinomas were found in 8% of patients, and 5.5% of patients had multiple endocrine neoplasia type 1. Surgical procedures included 106 enucleations (54%) and 92 pancreatic resections (46%). Mortality was nil. Rate of clinically significant pancreatic fistula was 18%. Enucleations had a higher reoperation rate compared with pancreatic resections (8.5% vs 1%; P = .02). Multiple endocrine neoplasia type 1 was significantly associated with younger age at onset (P < .005) and higher rates of malignancies and multiple lesions. Median follow-up was 65 months. Six patients (3%; 5 patients had neuroendocrine tumors grade G2) developed tumor recurrence. Four patients (2%) died of disease. New exocrine (1.5%) and endocrine (4%) insufficiencies were associated only with pancreatic resections.
Conclusions: Outcomes following surgical resection of insulinomas are satisfactory, with no mortality and good functional results. Recurrence is uncommon (3%), and it is more likely associated with neuroendocrine tumors grade G2. Insulinomas in multiple endocrine neoplasia type 1 are at higher risk for being malignant and multifocal, requiring pancreatic resections.