The spectrum of sonographic findings in pancreatic carcinoma.

The ultrasound studies of 59 patients with cancer of the pancreas were reviewed and the findings grouped into two categories: intrapancreatic, which included the appearance of the primary tumor and the pancreatic duct; and extrapancreatic, which included biliary obstruction, hepatic metastases, regional lymph node involvement, ascites, spleen enlargement and invasion, and alteration of the upper abdominal veins. Pancreatic duct dilatation was more evident with smaller tumors of the pancreatic head, while inferior vena cava compression was found not to be a constant finding even with large tumors of the head of the pancreas. Tumor extension to regional lymph nodes was difficult to detect and consequently underestimated. Nonvisualization, occlusion with or without collaterals, and displacement or deformity of the major branches of the portal venous system were detectable sonographically. The liver metastases of pancreatic carcinoma tended to be small and hypoechoic. This is a different pattern from that typically described for other gastrointestinal adenocarcinomas and, in particular, markedly different and distinguishable from the metastatic pattern seen with malignant pancreatic islet cell tumors. The significance of the intra- and extrapancreatic changes seen sonographically in cancer of the pancreas by ultrasound is discussed in relationship to clinical staging and prognosis.