Clinical experience in 37 cases of insulinoma
Insulinoma is the most frequent pancreatic islet cell tumor. Clinical manifestations include adrenergic and neuroglycopenic symptoms. Diagnosis is established through demonstration of inappropriately elevated insulin serum concentrations in the presence of hypoglycemia. The aim of this study is to show our experience in the management of insulinoma. Since 1988, 23 women (48 +/- 18 years) and 14 men (45 +/- 19 years) were studied. Seventy three percent of them suffered mainly from neuroglucopenic symptoms while 27% referred adrenergic signs. Mean duration of symptoms before diagnosis was 2.7 +/- 2 years. Mean fasting serum glucose was 32.4 +/- 8.7 mg/dl, insulin 38.2 +/- 39.7 microU/ml (RIA, n=11) or 23.8 +/- 18.1 microU/ml (chemoluminescence, n=26) and C-peptide 1.15 +/- 1.60 nmol/l (n=14). Twenty one patients developed clinical and/or biochemical hypoglycaemia within 9.0 +/- 5.2 hours of supervised fast. Preoperative localization was performed in 73% by imaging techniques, arterial calcium stimulation and/or intraoperative ultrasonography and palpation by the surgeon. Thirty six patients were operated on by conventional surgery in 25, or laparoscopic approach in 11 cases. In 22 patients, a solitary tumor was excised (61.1%). Six cases presented multiple insulinomas. Five patients had malignant insulinomas. In one case, a pattern of nesidioblastosis was found and 2 patients presented unspecific findings. In 3 patients another tumour (glucagonoma) was found (1 of them with MEN 1). One patient was treated with verapamil with good clinical response. Mean postoperative follow up was 60.4 +/- 59.9 months.