Incidental/Misdiagnosed Intrahepatic Cholangiocarcinoma and Combined Hepatocellular-Cholangiocarcinoma in Patients Undergoing Living Donor Liver Transplantation.

Background/Objectives: Mixed hepatocellular-cholangiocarcinoma and intrahepatic cholangiocarcinoma (CCA) are increasingly reported in patients with cirrhosis. Traditionally, these tumor types have not been considered indications for liver transplantation. We aimed to present our single-center experience for incidental CCA following liver transplantation. Methods: Among the 985 living donor liver transplantations, 261 cases were initially diagnosed as hepatocellular carcinoma. We retrospectively reviewed demographic data, preoperative radiological findings, pathology results, and postoperative outcomes. We classified tumors according to the Goodman classification. Results: Cholangiocarcinoma was identified in the explant pathology of 18 patients. According to the Goodman classification, five patients (27%) had type 1 tumors; eight (44.4%) had type 2 tumors; and five (27.8%) had sole CCA lesions. Tumor recurrence occurred in six patients (33.3%). The mean survival time was 61.6 ± 12 months. The mean disease-free survival was 10.67 ± 5.7 months. Disease-free survival times for Goodman type I, type II, and sole cholangiocarcinoma were 14.00 ± 5.57, 8 ± 5.66, and 6.00 ± 0.00 months, respectively. The 1-year and 5-year survival rates were 88% and 55%, respectively. Four patients died due to CCA; the remaining deaths were due to sepsis, COVID-19, amyotrophic lateral sclerosis, and lung squamous cell carcinoma. Conclusions: The misdiagnosed/incidental cholangiocarcinoma in transplanted patients with cirrhosis is rarely seen with high recurrence rates. Although transplant oncology is gaining prominence, preoperative evaluation and postoperative follow-up remain important.