Correlation of CT patterns of primary intrahepatic cholangiocarcinoma at the time of presentation with the metastatic spread and clinical outcomes: retrospective study of 92 patients.

OBJECTIVE: To study the CT appearance and histopathology of mass-forming intrahepatic cholangiocarcinoma (IHCC) at presentation and correlate these features with metastatic disease and patient survival.
MATERIALS AND METHODS: In this IRB-approved, HIPAA compliant retrospective study, we reviewed pathology database of 459 patients with cholangiocarcinoma seen from 2004 through 2013 to identify 92 patients with IHCC (48 women, 44 men, mean age 61 years) who had CT scans of primary tumor available for review. All baseline and follow-up CT's were reviewed by two radiologists in consensus to record imaging characteristics and metastatic patterns. Clinical and histopathology data were obtained from electronic medical records. Imaging patterns and histopathology were analyzed for associations with metastatic spread and survival.
RESULTS: Three distinct CT patterns of IHCC at presentation were identified: solitary dominant mass (type I IHCC, n = 34), dominant mass with satellite nodules in same segment (type II IHCC, n = 19), and multiple scattered hepatic lesions (type III IHCC, n = 39). Distant metastases developed in 49/92 patients (53%); 39 (42%) of which were present at diagnosis. Lungs (22/92; 24%), peritoneum (17/92; 18%), and bones (13/92; 14%) were most common metastatic sites. Type I IHCC had smaller size, lowest incidence of metastases at presentation, and best overall survival, while type III IHCC had shortest survival (p < 0.017). Poorly differentiated IHCC had higher proportion of osseous metastases (p = 0.042) and worse survival (p = 0.027).
CONCLUSION: IHCC has three distinct CT patterns at presentation with different prognoses. Knowledge of these patterns can help radiologists to detect the extrahepatic disease and predict prognosis.