Fusobacterium naviforme Liver Abscess Secondary to a Non-Meckelian Ileal Diverticulum Successfully Treated by Laparoscopic Resection After Failed Conservative Therapy.

Pyogenic liver abscess (PLA) is most commonly caused by Klebsiella pneumoniae or Escherichia coli of biliary or intestinal origin. Fusobacterium species are rare pathogens, and when identified, their possible sources include not only oral or pharyngeal lesions but also lesions of the lower gastrointestinal tract. We report the case of A 77-year-old female who presented with fever and anorexia. Laboratory findings showed an elevated white blood cell count and C-reactive protein (CRP). Contrast-enhanced CT revealed multiple liver abscesses in the right lobe and an abscess dorsal to the terminal ileum. Pus from ultrasound-guided drainage yielded Fusobacterium naviforme (F. naviforme). Despite carbapenem therapy and drainage, the infection persisted. Based on imaging findings suggestive of an ileal diverticulum as the source, laparoscopic ileocecal resection was performed. Pathology confirmed continuity between the diverticulum and a subserosal abscess cavity. Following surgery, the liver abscesses regressed markedly, and the patient was discharged on postoperative day 12. When Fusobacterium species are isolated from PLA, evaluation for lower gastrointestinal lesions should definitely be considered. Small abscesses (less than 3 cm) may resolve with antibiotics alone, but larger abscesses generally require drainage, and surgical intervention is indicated when conservative therapy fails or a persistent source is identified. To our knowledge, this is the first reported case of F. naviforme PLA arising from a non-Meckelian ileal diverticulum, successfully treated by surgery after the failure of conservative therapy.