Insulinoma of the Pancreas

ABSTRACT

Insulinoma is the most common functioning tumor of pancreas even though its prevalence is rare. The diagnosis and the treatment of insulinoma is very important because the tumor can induce critical and permanent neurologic deficit. We experienced ten patients with insulinoma and treated by surgical interventions at the Department of Surgery, Yonsei university college of medicine from 1983 to 1996. All the data were analysed retrospectively. The mean age of patient was 45 years (range 17 to 69) and the sex ratio of male to female was 12.3. The most common clinical manifestation was weakness. The preoperative mean levels of fasting blood sugar, plasma insulin, C-peptide, insulin to glucose ratio were 41(mg/dl), 40.07(U/ml), 4.03(ng/ml), 1.51, respectively. The detection rates of localizing tools on our cases were showed as follows THPVS(100% in 5 cases), EUS(67% in 3 cases), MRI(33% in 3 cases), CT scan(33% in 9 cases), angiography(33% in 6 cases) and US (20% in 10 cases). The intraoperative ultrasound(IOUS) was performed in the last three cases to try to find occult insulinoma and the relationship with main duct of pancreas in operative field. The types of surgical interventions were enucleation in 5 patients, distal pancreatectomy in 4 patients, pancreatoduodenectomy in 1 patient. The tumors were located in nearly equal frequencies over the entire pancreas head(30%), neck & body (30%), tail(40%). All of the tumors were single and 90% of them were solid and benign. The mean diameter of the tumors was 1.5cm. Symptoms of hypoglycemia and laboratory values such as fasting blood sugar, plasma insulin, C-peptide, insulin glucose ratio were improved in all the patient after operation. We suggest that the THPVS is the most sensitive preoperative test for localizing insulinomas and recommend the IOUS as a tool for detecting occult or multiple insulinoma and identifing the relationship with main duct of pancreas in operative field.