DIFFERENTIAL DIAGNOSIS OF ENDOSCOPIC RETROGRADE CHOLANGIO-PANCREATIOGRAPHIC FINDINGS BETWEEN CHRONIC PANCREATITIS AND PANCREATIC CANCER WITH SPECIAL REFERENCE TO CASES WITH OBSTRUCTION OR STENOSIS

Abstract

In an attempt to enhance efficacy of pancreatogram in the dif f erentical diagnosis between chronic pancreatitis and pancreatic cancer with special reference to cases with obstruction and stenosis of main pancreatic duct, we have evaluated the radiological findings of ERCP in proved cases of chronic pancreatitis and pancreatic cancer. Obstruction and stenosis of the main pancreatic duct were seen in 4 (6.7%) and 21 (35%) out of 60 cases with chronic pancreatitis and 29 (53.7%) and 20 (37%) out of 54 cases with pancreatic cancer. They were the most frequently observed findings to be difficult for differential diagnosis between chronic pancreatitis and pancreatic cancer. Among them, pancreatographic findings of distal part, stenotic or obstructive site and proximal part of the main pancreatic duct, cholangiographic findings and results of PS test were analysed. The following results were obtained. 1) As for pancreatographic findings in the distal part to obstruction or stenosis, there were found abnormalities in 88% of chronic pancreatitis and 64% of pancreatic cancer. However, the frequency of abnormal findings in the distal part were rather lower.(44%) in the cases with pancreatic cancer in which stenosis or obstruction were seen in body or tail. 2) Obstruction or stenosis with irregularity were characteristic of pancreatic cancer, but not of chronic pancreatitis except with pancreatolithiasis. In the other hand, localized narrowings were the most commonly observed findings to be difficult for differentiation. 3) In almost all cases with chronic pancreatitis and pancreatic cancer, proximal dilatation of the pancreatic duct were equally seen.4) Complete obstruction and stenosis with irregularity of the common bile duct were found exclusively found in cases with pancreatic cancer.5) As a whole, there were no differences between the results of PS test of chronic pancreatitis and pancreatic cancer. However, in the cases with pancreatic cancer in which the stenosis or obstruction was localized in tail, PS test was fairly well preserved.