Ultrasonographic evaluation of pancreatic cancers: size, contour, echo texture, and ductal configuration.

To improve the detection rate of small pancreatic tumors, it is important to know the characteristic differences in echographic patterns that distinguish small tumors from larger ones. We have studied the echographic patterns of histologically confirmed pancreatic cancers, with special reference to tumor size. The tumor size in 243 cases of adenocarcinoma determined by measurement of the pathological specimen correlated with that determined by ultrasonography. The ultrasonographic pancreatic configurations, tumor echo patterns, and pancreatic duct size and configurations were reviewed in accordance with the size of the tumor. Many pancreatic cancers showed localized swelling of the pancreas, however, more than half of all T1 cases had normal pancreatic contour, suggesting that we cannot rely on abnormal findings in configuration for the early diagnosis of pancreatic cancer. The very low echo pattern of tumor was seen only in T1 tumors. In cases in which the tumors were not detected by ultrasonography, the detection of a dilated pancreatic duct and common bile duct were very important clues to diagnosing a small tumor in the pancreas.