[Predictors of outcomes in surgery for hilar cholangiocarcinoma]

Characteristic of Perineural Invasion in Hilar Cholangiocarcinoma Based on Whole-Mount Histologic Large Sections of Liver

Background & Objective

Perineural invasion is an important biological feature of hilar cholangiocarcinoma (HCCA). We developed a whole-mount histologic large sections (WHLS) of the liver to evaluate peripheral nerve invasion (PNI) of HCCA.

Methods

Using sampling, fixation, dehydration, embedding, sectioning, hematoxylin and eosin (H&E) and immunohistochemical (IHC) staining, and scanning, the characteristics of intrahepatic and extrahepatic PNI in 20 patients with Bismuth type III and type IV HCCA were analyzed with WHLS. Correlation between the characteristics of nerve invasion and tumor size, vascular invasion (artery, portal vein), degree of differentiation, microvascular invasion (MVI), carbohydrate antigen19-9 (CA19-9), and differentiation degree of HCCA was statistically evaluated.

Results

The WHLS of the liver was successfully established, which enabled us to observe intrahepatic and extrahepatic distribution of HCCA and whether surrounding tissues including nervous, blood, and lymph vessels were infiltrated. Extrahepatic and intrahepatic PNI were identified in 20 (100%) patients and 1 (5.0%) patient, respectively. Vessel density decreased in most invaded nerves presented by CD-34, which correlated with 100% of poorly differentiated and 83% of moderately differentiated tumors (P<0.008).

Conclusion

This study established a WHLS of the liver that can be used for clinical diagnosis and research, and confirmed that extrahepatic PNI is prevalent, but intrahepatic nerve invasion is rare and does not accompany the invasion scope of bile ducts in types III and IV HCCA. In addition, moderately and poorly differentiated malignant tumors are more prone to PNI, independent of blood supply.

Perineural invasion of hilar cholangiocarcinoma in Chinese population: One center’s experience

BACKGROUND

Hilar cholangiocarcinoma (HCCA) often produces perineural invasion (PNI) extending to extra-biliary sites, while significant confusion in the incidence of PNI in HCCA has occurred in the literature, and the mechanism of that procedure remains unclear.

AIM

To summarize the incidence of PNI in HCCA and to provide the distribution of nerve plexuses around hepatic portal to clinical surgeons.

METHODS

Reported series with PNI in HCCA since 1996 were reviewed. A clinicopathological study was conducted on sections from 75 patients with HCCA to summarize the incidence and modes of PNI. Immunohistochemical stains for CD34 and D2-40 in the cancer tissue were performed to clarify the association of PNI with microvessel and lymph duct. Sections of the hepatoduodenal ligament from autopsy cases were scanned and handled by computer to display the distribution of nerve plexuses around the hepatic portal.

RESULTS

The overall incidence of PNI in this study was 92% (69 of 75 patients), while the rate of PNI in HCCA in the literature ranging from 38% to 100%. The incidence of PNI did not show any remarkable differences among various differentiated groups and Bismuth-Corlette classification groups. Logistic regression analysis identified the depth of tumor invasion was the only factor that correlated significantly with PNI (P < 0.01). In spite of finding tumor cells that could invade microvessels and lymph ducts in HCCA, we did not find tumor cells invaded nerves via microvessels or lymph ducts. Three nerve plexuses in the hepatoduodenal ligament and Glisson’s sheath were classified, and they all surrounded the great vessels very closely.

CONCLUSION

The incidence of PNI of HCCA in Chinese population is around 92% and correlated significantly with a depth of tumor invasion. It also should be considered when stratifying HCCA patients for further treatment.