OBJECTIVE. The purpose of this study was to discern clinical and imaging features for differentiating intraductal metastasis from double primary intraductal cholangiocarcinoma in patients with a history of extrabiliary malignant disease.
MATERIALS AND METHODS. Over a 10-year period, the cases of 14 patients with histopathologically proven intraductal metastasis (n = 8) or double primary intraductal cho�langiocarcinoma (n = 6) who had a history of extrabiliary malignancy were identified. Two radiologists retrospectively reviewed CT (n = 14) and MR (n = 6) images for the size and ap�pearance of the intraductal lesion, presence of a parenchymal mass, multiplicity, attenuation on arterial and portal phase images, and presence of calcification. Clinical findings such as the location of extrabiliary malignancy and presence of Clonorchis sinensis infestation also were recorded. Univariate tests were used to differentiate the two disease entities.
RESULTS. Histopathologic confirmation was obtained by surgical resection (n = 12) or ultrasound-guided biopsy (n = 2). All intraductal metastatic lesions were of colorectal cancer, and all intraductal cholangiocarcinomas were associated with extracolonic malignant dis�ease, including three cases of gastric cancer (p
CONCLUSION. When an intraductal lesion is found in a patient with extrabiliary ma�lignancy, the presence of a contiguous parenchymal mass, an expansile nature of the intra�ductal lesion, and a history of colorectal cancer may suggest the presence of intraductal me�tastasis rather than double primary intraductal cholangiocarcinoma.