Cancer cells spread through lymph vessels in the submucosal layer of the common bile duct in gallbladder carcinoma

Introduction

In the present study, we performed immunohistochemical staining with a lymphatic epithelium-specific marker, D2-40, to analyze the status of lymphatic spreading in the hepatoduodenal ligament in T2 gallbladder carcinoma (GC).

Methods

One hundred and eighty-six paraffin-embedded specimens from 15 T2 GC patients were reviewed.

Results

Lymph vessels lined with D2-40 were visualized in the submucosal layer of the common bile duct in all cases. In 3 of 15 patients, clusters of cancer cells were identified in the submucosal lymph vessels of the extrahepatic bile duct, and this lymphatic invasion of cancer cells failed to be detected with only conventional hematoxylin–eosin staining. The frequency of the invasion to the submucosal lymph vessels in T2 GC correlated with presence of microscopic invasion to hepatoduodenal ligament and perineural invasion.

Conclusion

There were lymph vessels in the submucosal layer of the common bile duct, and cancer cells can spread through these channels in addition to the large lymph vessels in subserosal layer around the extrahepatic bile duct in GC. The present results would support the concept of en bloc resection of the extrahepatic bile duct in curative resection for T2 GC.