Detection of pancreatic tumors by ultrasound during surgery.

Real-time B-mode ultrasonic scanning was performed during 14 operations for pancreatic tumors. All operations were for adenocarcinoma, except in one patient with a Zollinger-Ellison tumor. The ultrasonic tissue appearance of pancreatic carcinoma was not specific. However, ultrasonic signs of pancreatic duct dilation, striction or invasion of the superior mesenteric veins, and common bile duct involvement may help to establish the diagnosis of malignancy. A triad of ultrasound signs indicative of malignant obstruction of the common bile duct consisted of (1) dilation, (2) absence of biliary stones, and (3) a distinctive termination pattern of the duct. Operative ultrasound was used to guide a biopsy needle to obtain pancreatic tissue samples. The Zollinger-Ellison tumor of the pancreas produced a sonolucent appearance that clearly distinguished it from the surrounding tissue.