Cryptogenic pyogenic liver abscess as the herald of colon cancer

Colonic mucosal defects might be a route for bacterial invasion into the portal system, with subsequent hematogenous spread to the liver. We retrospectively investigated the results of colonoscopy and the clinical characteristics of patients with pyogenic liver abscess of colonic origin.

A total of 230 consecutive patients with pyogenic liver abscess were reviewed between 2003 and 2010. The 230 patients were categorized into three groups (pancreatobiliary [n = 135], cryptogenic [n = 81], and others [n = 14]). Of the 81 cryptogenic patients, 37 (45.7%) underwent colonoscopy. Colonic lesions with mucosal defects were considered colonic causes of abscess.

In the 37 colonoscopic investigations, colon cancer was found in six patients (16.2%), laterally-spreading tumor (LST) in two patients (5.4%), multiple colon ulcers in one patient (2.7%), colon polyps in 17 patients (45.9%), and diverticula in four patients (10.8%). Nine (11%) of 81 cryptogenic abscesses were therefore reclassified as being of colonic origin (colon cancer = 6, LST = 2, ulcer = 1). Three cases were stage III colon cancer, and the others were stage I. Two LST were high-grade dysplasia. The percentage of patients with Klebsiella pneumoniae (K. pneumoniae) and diabetes mellitus (DM) of colonic origin was 66.7%, which was significantly higher than the 8.6% for other causes (P < 0.001).

Of the 37 patients with cryptogenic pyogenic liver abscess who underwent colonoscopy, nine (24.3%) were diagnosed with a colonic cause. Colonoscopy should be considered for the detection of hidden colonic malignant lesions in patients with cryptogenic pyogenic liver abscess, especially for patients with K. pneumoniae and DM.