Insulinoma Identified from Insulin and C-peptide Determinations by Pancreatic Vein Catheterization

Abstract

Reliable preoperative localization of insulinoma is necessary to avoid reoperation. Arteriography has been considered the most valuable method for the preoperative localization of an insulinoma in the pancreas. However, the accuracy of localization is only 50 or 60%.
A patient was repeatedly subjected to selective angiography of the celiac and superior mesenteric artery, but no tumor could be demonstrated by this method, and the symptoms did not respond to medical therapy. Percutaneous transhepatic catheterization of the pancreatic vein was carried out and the levels of plasma insulin and C-peptide from the head of the pancreas were found to be 540μU / ml and 18.0 ng/ml, respectively. We confirmed a small tumor in the head of the pancreas on operation. Following surgery, the symptoms of hypoglycemia completely disappeared.
If no tumor is found at operation, and medical treatment has already failed, distal partial pancreatectomy would be indicated. However, this may be unsatisfactory since it removes only 25 to 55% of insulinomas. Therefore, if no tumor is found on arteriography, selective catheterization of the panceatic veins via a transhepatic route should be tried.