Characterization of intrahepatic cholangiocarcinoma of the intraductal growth-type and its precursor lesions.

A cohort of patients with intraductal growth-type intrahepatic cholangiocarcinoma (IG-ICC) and its precursor lesions, collectively termed intraductal papillary neoplasm of the liver (IPNL), was characterized with respect to demographics, clinical manifestations, perioperative management, long-term survival, and molecular features associated with carcinogenesis. A total of 122 patients with IPNL types 1 through 4, 108 patients with non-IG-ICC and 210 patients with hepatolithiasis alone were studied. Expression of CDX2, TFF1, MUC1, MUC2, MUC5AC, EGFR, and p53 was determined by using immunohistochemistry. Females predominated in those with hepatolithiasis alone and IPNL. The mean age of patients with hepatolithiasis alone was 6 to 8 years younger than that of those with IPNL. The association with hepatolithiasis in patients with IPNL types 1 and 2, IPNL types 3 and 4, and non-IG-ICC was 100%, 79%, and 64%, respectively. Mucobilia, anemia, and elevated serum carcinoembryonic antigen levels were helpful in distinguishing IG-ICC and its precursor lesions. The mean survival of patients with IPNL type 3, IPNL type 4, and non-IG-ICC was 55.5 months, 36.9 months, and 15.8 months, respectively. The incidence of expression of CDX2 and TFF1 was maximal in IPNL type 3. Expression and cellular distribution of MUC2 and CDX2 were similar. MUC5AC was strongly expressed in all patients with IPNL; EGFR and p53 were rarely expressed in patients with IPNL. In conclusion, hepatolithiasis appears to be a precipitating factor in the development of IPNL. Signs of mucobilia were specific for the diagnosis of IPNL. Expression of CDX2 and MUC2 are helpful in differentiating IPNL and non-IG-ICC. Significant differences in survival associated with the various lesions studied warrants a more aggressive surgical strategy in their management.