Hepatic infestation of Echinococcus multilocularis with extension to regional lymph nodes.

Objective: The objective of this paper is to prove lymph node infestation by Echinococcus multilocularis and provide evidence for systematic lymph node dissection in curative resections for alveolar echinococcosis (AE).
Background: Human AE is a life threatening parasitic condition, usually caused by an intrahepatic infiltrative and destructive growth of the larvae E. multilocularis. WHO guidelines provide radical hepatic resection for curative treatment. However, the current norms do not consider dissection of regional lymph nodes. No report to date has visualized concurrent lymph node infestation.
Methods: Radical excision of infested liver including regional lymph nodes with subsequent histological examination was carried out in a patient suffering from AE. The literature was reviewed and a revised state-of-the-art treatment of AE deduced.
Results: Upon inspection the liver displayed macroscopic features of AE, in contrast to the regional lymph nodes which appeared unsuspicious. Further histological analysis confirmed regional lymph node infestation of E. multilocularis.
Conclusions: This is the first publication on histological evidence of E. multilocularis in regional hepatic lymph nodes, and thus, demonstrating dissemination from the liver. Since AE can spread through lymphatic drainage, even without causing macroscopic conspicuity, resection should not be resumed to the liver tissue only, but rather to consider the routine removal of regional lymph nodes as well. Omission of lymph node dissection can leave behind parasitic tissue and surgical procedures erroneously judged as curative.