Association of Biliary Source Klebsiella pneumoniae Pyogenic Liver Abscess With Colon Adenocarcinoma: A Case Report

Background Pyogenic liver abscesses (PLAs) commonly result from hematogenous spread or biliary tract infections, most often due to cholecystitis or cholangitis. Klebsiella pneumoniae is a recognized pathogen in PLA and has been associated with underlying gastrointestinal malignancies, particularly colorectal cancer. While screening for malignancy is well established in cryptogenic K. pneumoniae liver abscess, its role when a clear biliary source is present is less well described. Case Presentation We report a 76‐year‐old man with a history of untreated hepatitis C and prior renal cell carcinoma who presented with right upper quadrant pain, weight loss, and leukocytosis. Imaging revealed a pericholecystic liver abscess with acute cholecystitis. The abscess was drained percutaneously, and cultures grew K. pneumoniae . Although imaging suggested a biliary source, colonoscopy was performed given the pathogen’s known association with colorectal neoplasia. This revealed multiple large laterally spreading tumors, including a 30‐mm ascending colon lesion confirmed as well‐differentiated invasive adenocarcinoma on biopsy. Conclusion This case underscores the importance of considering colorectal cancer screening in patients with K. pneumoniae PLA, even when a biliary source is identified. Early endoscopic evaluation in such patients may facilitate timely diagnosis of occult malignancy and alter clinical management.