Incidental Hepatocellular Carcinoma after Liver Transplantation: Clinicopathologic Features and Prognosis

Background: The prognostic impact and clinicopathologic features of incidental hepatocellular carcinoma (iHCC) detected in explanted livers of patients undergoing liver transplantation (LT) has been a controversial issue in previous studies when compared with patients who are diagnosed with hepatocellular carcinoma (pdHCC) before LT. We aimed to review and compare these patient groups in a high-volume LT center. Methods: The present study involves a retrospective analysis of 406 HCC patients who received LT between January 2002 and April 2022. Among these patients, demographic data, histopathologic features and prognosis for iHCC and pdHCC were evaluated. Results: In our series, 406 patients' final diagnosis was HCC after they had received LT, nevertheless 54 patients in this HCC group were diagnosed incidentally after the pathological evaluation of the explanted livers. The etiology of the underlying liver disease between pdHCC (n = 352) and iHCC (n = 54) groups had some differences in our study population. Most of the patients in the pdHCC group had moderately differentiated tumors (45.7%). On the other hand, most of the patients in the iHCC group had well differentiated tumors (79.6%). There were 158 (44%) patients who met the Milan criteria in the pdHCC group while there were 48 (92%) patients in the iHCC group (p < 0.001). IHCC patients had statistically better 1, 3, 5 and 10 years disease-free and overall survival rates when compared with pdHCC patients. There was only 1 (1.8%) patient who had tumor recurrence in the iHCC group while 76 (21%) patients had tumor recurrence in the pdHCC group (p = 0.001). There is no disease free and overall survival difference when iHCC patients are compared with pdHCC patients who met the Milan criteria. Conclusion: It is the first study to show that iHCC patients may differ from pdHCC patients in terms of etiological features. IHCC tumors show better histopathologic features than pdHCC with low recurrence rate and iHCC patients have better survival rates than pdHCC patients.