Correlation between spiral computed tomography, endoscopic ultrasonography and findings at operation in pancreatic and ampullary tumours.

BACKGROUND: Spiral computed tomography (CT) allows high-resolution examination of the pancreas, surrounding vascular structures, lymph nodes and liver. Endoscopic ultrasonography (EUS) also allows high-resolution imaging of the pancreas and adjacent structures but is an invasive procedure. With the availability of spiral CT, the role of EUS in the investigation of patients with suspected pancreatic or ampullary tumours is unclear.

METHODS: Forty-eight patients with clinical suspicion of a pancreatic or ampullary tumour underwent both spiral CT and EUS. Thirty-four patients had surgical exploration, of whom 17 underwent pancreatic resection and 17 had biliary and gastric bypass. The results of spiral CT and EUS were compared with the operative findings.

RESULTS: The final histological diagnosis was ductal adenocarcinoma (24 patients), ampullary carcinoma (six), serous cystadenoma (two) and chronic pancreatitis (two). EUS demonstrated 33 and spiral CT 26 of the 34 primary lesions. EUS was particularly useful in the assessment of small resectable tumours missed by spiral CT. The sensitivity and specificity of EUS and spiral CT for detecting involvement by the tumour of the superior mesenteric vein, portal vein and lymph nodes were similar, but EUS was less effective at evaluating the superior mesenteric artery.

CONCLUSION: EUS is an important additional investigation after spiral CT in patients with a suspected pancreatic or ampullary tumour.