A rare case of gallbladder cancer with giardiasis.

A 72-year-old man was referred to our hospital for suspected gallbladder cancer. We performed cholecystectomy with liver bed resection and lymph node dissection. Intraoperative cytological examination of the bile juice revealed some trophozoites of Giardia lamblia, and pathological examination revealed gallbladder cancer. Therefore, we diagnosed giardiasis associated with gallbladder cancer. We administered 750 mg per day metronidazole for 10 days. The patient was a farmer by occupation and used animal manure for agricultural purposes; he also consumed his own harvest, which was recognized as the infection route for his giardiasis. We reviewed the literature and found very few cases of giardiasis associated with gallbladder cancer.