A Case of Multiple Insulinoma Demonstrated by Percutaneous Transhepatic Catheterization and Insulin Radioimmunoassay

Abstract

The major difficulty in surgery for insulinomas occurs when no lesion can be palpated at exploration. Blind partial pancreatectomy is unsatisfactory since it removes only 25 to 55% of insulinomas. About 10% of the benign tumors are multiple and the tumors may be found outside the pancreas. Also they are apt to be overlooked at exploration. In 15-30% of patients with insulinoma, additional surgery is required.
Preoperative localization of insulinomas by arteriography is successful in only about 66% of cases. Additional preoperative studies on localization procedures are thus required.
Percutaneous transhepatic catheterization of the portal system and blood sampling for insulin radioimmunoassay were performed in a 16-year-old male with clinical evidence suggesting the presence of an insulinoma after negative selective arteriography. “Step-up” gradients in insulin levels occurred at two sites and provided good evidence for the presence of two secreting tumors in the head and tail of the pancreas.
A tumor blush was demonstrated at the head of the pancreas by repeated super-selective dorsal pancreatic arteriography, but not tumor was indicated in the tail of the pancreas.
At surgery, a small adenoma (1.5×1.0 cm) was found in the head of the pancreas as predicted by both arteriography and the catheterization procedure, and on careful palpation a very small adenoma (0.5×0.6 cm) was also found in the tail of the pancreas as predicted by the catheterization procedure.
Our experience with this patient suggests that the present catheterization procedure may be very useful for the preoperative identification of insulin-producing tumors of the pancreas.