Right colon adenocarcinoma presenting as Bacteroides fragilis liver abscesses.

Pyogenic abscesses of the liver occur in association with a variety of diseases. Sometimes they are caused by anaerobic infections of liver metastases. Uncommonly, however, multiple hepatic abscesses caused by anaerobic bacteria are the presenting signs of unsuspected colonic cancer in the absence of liver metastases. We report a 60-year-old man who presented with febrile cholestatic liver disease initially thought to be metastases. Repeated ultrasound-directed liver biopsies yielded a diagnosis of multiple abscesses. Bacteroides fragilis was grown from the liver specimen and the patient responded well to metronidazole treatment. Two months later, however, overt symptoms of large bowel disease led to the diagnosis of colonic adenocarcinoma. After a 6-month postoperative follow-up, the patient is free of liver metastases. Anaerobic liver abscesses should always alert the clinician to possible silent colonic cancer.