Clinical application of endoscopic ultrasonography in the diagnosis of periampullary lesions

Background: Demonstration of duodenal periampullary lesions, especially small tumors, is difficult with many imaging modalities, such as abdominal ultrasonography (US), abdominal computed tomography (CT), percutaneous transhepatic cholangiography (PTC) and endoscopic retrograde cholangiopancreatography (ERCP) and/or magnetic resonance cholangiopancreatography (MRCP). Endoscopic ultrasonography (EUS) provides good imaging results for the ampullopancreatic region. This study presents a clinical assessment of EUS for periampullary lesions. Patients and Methods: A total of 12 patients who had periampullary lesions studied by abdominal US, abdominal CT, PTC, ERCP, and/or MRCP all underwent this EUS study. Eleven patients received surgical treatment and one received endoscopic papillotomy with stone retrieval. The surgical findings and pathologic diagnoses in their final states were compared with the EUS findings. Results: Among nine ampullary small tumors (mean size, 1.7 cm; range, 0.9-2.5 cm), EUS produced a good demonstration of small ampullary tumors, obtaining accuracy of tumor invasion of 88.9% (8/9). EUS found small stones at the distal common bile duct (CBD) in five cases that were not shown on the other imaging modalities. However, EUS failed to detect an ampullary tumor with stent in place and could not delineate a coexisting hilar tumor invading the common hepatic duct. Conclusion: EUS is an accurate tool for the diagnosis and staging of small ampullary tumor (< 3 cm) with local invasion, and for stones in the distal CBD. However, EUS has its limitations in ampullary tumors with stent in place and in the finding of coexisting liver hilar tumors. Nevertheless, EUS is an important imaging modality in aiding the diagnosis and treatment decisions for periampullary lesions.