Rapidly growing mucinous cholangiocarcinoma.

A 65-year-old man was hospitalized due to an abdominal tumor. Several imaging studies showed multilocular tumors in the right hepatic lobe and in the pancreatic head, 4 and 7 cm in size, respectively. The hepatic tumor rapidly grew to 9 cm in 4 weeks, associated with a rapid increase in the serum carcinoembryonic antigen level from 125 ng/ml to 1,000 ng/ml. The pathologic diagnosis of the resected liver tumor was mucinous cholangiocarcinoma. This hepatic tumor produced a large amount of mucin, but did not secrete mucin into the bile ducts. Therefore, there was no obstructive jaundice. The incidentally accompanied pancreatic tumor was a typical serous cystadenoma. The present case suggested that mucinous cholangiocarcinoma could present rapid growth of the tumor. The clinicopathological features of mucinous cholangiocarcinoma are demonstrated for the first time, and the differences between mucinous cholangiocarcinoma and mucin-producing papillary adenocarcinoma of duct-spreading type are discussed.