Excretion of necrotic hepatocellular carcinoma tissues into the biliary system after transcatheter arterial chemoembolization

Aim To evaluate the incidence and condition of necrotic tumor excretion into the biliary system in patients with hepatocellular carcinoma (HCC) >5 cm treated with conventional transcatheter arterial chemoembolization (TACE). Methods Eighty-three patients who underwent TACE for newly developed HCC >5 cm without an intraductal tumor thrombus and were followed-up by computed tomography for longer than 6 months were eligible. According to the location, the maximum tumors were divided into central (in contact with the left or right hepatic duct, n = 39) or peripheral (not in contact with them, n = 44). When high-density material in the biliary system that was not seen on pretreatment computed tomography was identified, it was determined as excreted necrotic tumor tissue containing iodized oil. The incidence, interval between TACE and occurrence of the necrotic tumor excretion, and clinical course were evaluated. Results Tumor excretion into the biliary system was identified in nine (10.8%) patients with a central tumor (mean diameter, 85.0 ± 29.6 mm) 28–433 days (mean, 219.3 ± 128.2) after the initial TACE. In one patient, the necrotic tumor cast caused cholangitis 1203 days after the initial TACE, and was endoscopically removed. Infection of the embolized tumor developed in two cases and percutaneous drainage was carried out 105 and 158 days later, respectively. Conclusions Excretion of necrotic tumors into the biliary system after TACE was not rare in patients with centrally located HCC >5 cm. The detached tumor rarely caused symptoms and the communication between the tumor and bile duct caused the infection of tumors.