IMAGING OF PERIPHERAL CHOLANGIOCARCINOMA - COMPARISON WITH PATHOLOGICAL FINDINGS

Objective. - Peripheral cholangiocarcinoma is a rare malignant intrahe patic tumor which originates in the distal bile duct. Our purpose was to identify the imaging characteristics of peripheral cholangiocarcino ma and to establish a correlation with surgical and histopathologic fi ndings. Methods and materials. - The imaging data of 16 patients with proven cholangiocarcinoma were retrospectively reviewed by sonography in 13 cases, computed tomography in 13 cases, magnetic resonance imagi ng in 6 cases, and angiography in 10 cases and correlated with surgica l and histopathologic findings. Results. - In most cases peripheral ch olangiocarcinoma appeared as a single, large (> 10 cm), heterogeneous, and non encapsulated mass. On precontrast computed tomography, the le sions were mostly low density. Enhancement was moderate in the bolus p hase and increased in the delayed scan. With magnetic resonance imagin g, lesion signals were low intensity in T1-weighted images and variabl e intensity in T2-weighted images. On angiogram, lesions were often hy povascular. Associated features were frequently observed: portal encas ement (69%), lobar atrophy or capsular retraction (43%), dilated intra hepatic bile ducts (30%), extension into the hepatic capsule (23%), an d inferior vena cava extension (15%). Radiopathologic comparison showe d that imaging modalities accurately identified vascular encasement, b ut underestimated extrahepatic tumor extension. Conclusion. - In most cases, peripheral cholangiocarcinoma has a typical appearance which ma y be helpful in differentiating this disease from other intrahepatic t umors.