Alveolar echinococcosis in a metropolitan area resident

This case report describes a 35-year-old female resident of a metropolitan area of Japan who presented with clinical symptoms of apparent gallbladder cancer and liver metastasis. After an extended right hepatic lobectomy, a resected lesion comprising four tumors (≤40 mm in diameter) was histopathologically confirmed as alveolar echinococcosis (AE). Although endemic in Japan, AE rarely arises in the mainland, because the causative pathogen, Echinococcus multilocularis, is distributed only in Hokkaido. The patient had visited Hokkaido twice, but she denied any behavior or history that would potentially relate to AE during these visits. A more detailed history revealed that she had kept a stray dog that her husband had picked up from a road in eastern Hokkaido. Although the dog showed no evidence of Echinococcus infection, the possibility of acquiring AE from the dog should be considered.