Hepatocellular carcinoma with tumor thrombus in bile duct: A proposal of new classification according to resectability of primary lesion.

Background: Hepatocellular carcinoma (HCC) with tumor thrombus in the bile duct (BDTT) is easily misdiagnosed or mistreated due to the clinicopathological diversity of the thrombus and its relationship with primary lesions.

Aim: To propose a new classification for HCC with BDTT in order to guide its diagnosis and treatment.

Methods: A retrospective review of the diagnosis and treatment experience regarding seven typical HCC patients with BDTT between January 2010 and December 2019 was conducted.

Results: BDTT was preoperatively confirmed by computed tomography/magnetic resonance imaging in only four patients. Three patients with recurrent HCC and one patient with first-occurring HCC had no visible intrahepatic tumors; of these, misdiagnosis occurred in two patients, and three patients died. One patient was mistreated as having common bile duct stones, and another patient with a history of multiple recurrent HCC was misdiagnosed until obvious biliary dilation could be detected. Only one patient who received hepatectomy accompanied by BDTT extraction exhibited disease-free survival during the follow-up period. A new classification was proposed for HCC with BDTT as follows: HCC with microscopic BDTT (Type I); resectable primary or recurrent HCC mass in the liver with BDTT (Type II); BDTT without an obvious HCC mass in the liver (Type III) and BDTT accompanied with unresectable intra- or extrahepatic HCC lesions (Type IV).

Conclusion: We herein propose a new classification system for HCC with BDTT to reflect its pathological characteristics and emphasize the significance of primary tumor resectability in its treatment.