Case Presentation: A 34-year-old man with a recent history of perforated appendicitis was admitted with a 2-week complaint of nausea, vomiting, abdominal pain and fever. His past history only included an appendectomy 6 months prior, with no history of intravenous drug use, prior diverticulitis, or biliary disease. On exam, he was febrile to 101.1°F, tachycardic, hypotensive, anicteric, and had right upper quadrant tenderness. His labs were notable for a white blood cell count of 18,200 and an alkaline phosphatase level of 255. A CT scan of abdomen and pelvis with contrast showed a 6 x 9 cm bilobed “double target” lesion with rim enhancement in the liver, suspicious for a hepatic abscess. The patient underwent CT-guided drainage of the abscess, and culture grew some E. coli and many Bacteriodes fragilis. Blood cultures remained negative. The patient was treated with in-situ drainage and IV piperacillin-tazobactam and metronidazole for 14 days, followed by oral ciprofloxacin and metronidazole to complete a 4-week course. A repeat CT scan 6 weeks after discharge showed resolution of the liver abscess.
Discussion: This patient’s history of perforated appendix was the likely etiology of his liver abscess. Appendicitis was once the primary source for development of hepatic abscesses, but due to imaging and expedient diagnosis, it now accounts for fewer than 10% of cases. Late presentations are rare, with most cases occurring just weeks after the original illness. It is unclear what accounts for such a delayed presentation in our patient. Most liver abscesses are associated with biliary tract disease and are caused by E. coli and Klebsiella. Bacteriodes fragilis is an uncommon etiology, as it is found in the gut flora. Case reports have suggested that infections may spread from perforated retrocecal appendicitis into the peritoneal and subhepatic spaces entering the liver through blood vessels, the biliary tract, or directly through contiguity. In our patient, the abscess was present in the inferior posterior right lobe of the liver, which may suggest a perinephric spread. Additionally, while blood cultures may be negative, polymerase chain reaction (PCR) may be positive. While B. fragilis is covered by the usual empiric antibiotics for pyogenic liver abscess, such as piperacillin-tazobactam and metronidazole, multidrug resistant (MDR) forms resistant even to carbapenems have been reported. It is important for internists to take into account a history of a perforated appendix as it can be a rare but dangerous precursor to a pyogenic liver abscess. Early treatment and intervention are vital to preventing mortality in hepatic abscesses.
Conclusions: Although pyogenic liver abscesses are more common soon after appendicitis, patients can present with complications even several months after appendicitis. Prompt drainage is vital and helps identify the causative organism.
