Patterns of Caudate Lobe Invasion of Hilar Cholangiocarcinoma: A Panoramic Histologic Study of Liver.

BACKGROUND

At present, caudate lobectomy (CL) in hilar cholangiocarcinoma (HCCA) was controversial. Our study was designed to investigate the features of caudate lobe invasion (CLI) by whole-mount histologic large sections (WHLS).

METHODS

A total of 46 HCCA patients underwent hemihepatectomy or trisectionectomy combined with CL were included. Serial WHLS (120 mm × 100 mm) were collected, and the relationship between caudate lobe and tumor was retained to determine the incidence of CLI. Hematoxylin and eosin (HE) and immunohistochemical (IHC) staining were completed to further explore the pathway of CLI.

RESULTS

The whole region of the Glisson system in caudate lobe and hilar area can be clearly displayed by WHLS, and 32 (32/46 69.6%) patients were identified with CLI. There were three different pathways of CLI with panoramic IHC staining. The most common pathway is through the fibrous connective tissue along Glisson system (20/32 62.5%, without carcinoma in bile ducts). The Bismuth type, tumor size, vascular invasion, pathological type, and hepatic invasion were related to the CLI (p < 0.05).

CONCLUSIONS

The incidence and distribution of CLI provided histologic evidence for CL in HCCA. Based on the invasion pathway, it is necessary to assess the fibrous connective tissue in Glisson system of caudate lobe in pathological research and practice.