Imaging and staging of biliopancreatic malignancy: Role of ultrasound

Most patients with a pancreatic head carcinoma, periampullary carcinoma or a cholangiocarcinoma of the liver hilum (Klatskin tumor) present with obstr uctive jaundice and therefore ultrasound often is the first imaging modalit y. Visualization is sufficient in more than 90% of cases for adequate diagn osis and staging. Even most small papillary tumors can be diagnosed with co nventional abdominal ultrasound. In pancreatic head and periampullary carci noma vascular involvement is the most important determinant for local irres ectability and can often be assessed by color Doppler US. An abnormal pulse d Doppler signal obtained from the portal venous system due to severe narro wing or occlusion is highly suspicious for major involvement and irresectab ility of the tumor. However, a normal pulsed Doppler signal does not exclud e involvement, if the tumor has continuity with the vessel with interruptio n of the hyperechoic tumor vessel interface. Enlarged lymph nodes are not a major diagnostic parameter, because a reliable differentiation between rea ctive and malignant lymph nodes is generally not possible. Very tiny liver and peritoneal metastases are missed by abdominal US and only detectable by laparoscopy and/or laparascopic US. In cholangiocarcinoma of the liver hil um extensive biliary and vascular involvement are considered the most impor tant factors for determining irresectability. Portal venous involvement can be assessed by color Doppler US with a high accuracy (91%). Although chola ngiography (ERCP and PTC) is considered the best imaging modality in detect ing proximal extension of the tumor into the biliary system US can provide useful additional information. If dilated ducts are seen without clear comm unication among each other within a liver lobe, extension of the tumor into the segmental bile ducts can be concluded. We consider color Doppler US, a valuable tool for preoperative imaging and staging of biliopancreatic malignancy.