S5789 Pus Without Pathogen: A Surprising Case of Multiple Sterile Pyogenic Liver Abscesses

Introduction: Pyogenic liver abscesses (PLA) are localized collections of pus within the liver, typically arising from biliary disease, malignancies, or diabetes. A subset known as cryptogenic liver abscesses (CLAs) occurs without an identifiable source. We discuss a case of a liver abscess with no known etiology, examining its clinical course, treatment approach, and potential underlying factors. Case Description/Methods: A 59-year-old man with a history of treated hepatitis C presented with 1-2 weeks of fever, night sweats, decreased appetite, vomiting and generalized abdominal pain. He was noted to be afebrile with stable vital signs. Labs were notable for leukocytosis and an elevated alkaline phosphatase. Computed tomography (CT) abdomen and pelvis showed 3 hypodense masses throughout the liver concerning for multifocal abscesses further confirmed by MRI. Tumor markers were negative. HIV, respiratory, blood and urine cultures were negative. Hepatitis panel revealed a reactive hepatitis C antibody with a negative hepatitis C PCR. He was started on vancomycin, cefepime and piperacillin/tazobactam. Interventional radiology (IR) initially placed 2 drains leading to partial abscess improvement, however a residual collection remained unchanged, prompting placement of a third drain. Antibiotics were de-escalated. Infectious workup performed on all drain specimens returned negative for bacteria, fungi and tuberculosis. Despite negative culture data, he was transitioned to oral ciprofloxacin and metronidazole due to the size and number of his abscesses. He was then discharged. All 3 drains were removed a month later outpatient and repeat CT imaging revealed resolution of abscesses. Discussion: While many cases of PLA have identifiable causes, a significant proportion remain cryptogenic with no apparent source of infection. This raises important questions about the pathogenesis and management of CLAs. The case described above underscores the complexities of PLA management, particularly in patients requiring multiple IR interventions for persistent collections. Given these uncertainties, there is a clear need for further research to better understand the pathophysiology of CLAs and refine treatment strategies. Identifying potential risk factors and improving diagnostic precision could ultimately enhance patient outcomes and target therapeutic approaches. As illustrated by our patient’s case, persistent abscess collections necessitate a dynamic approach, integrating IR-guided interventions with antimicrobial therapy.