Newly Diagnosed Liver Abscess: Colonoscopy Required

Abstract

Introduction: Liver abscesses occur as the result of pyogenic or amoebic infection and are more commonly found in immunodeficient patients. Their occurrence is very rare and only accounts for 0.02% of all hospital admissions. Klebsiella pneumonia and Pseudomonas aeruginosa are the most common causes of liver abscesses especially in Eastern Asian countries. We report a case of a liver abscess mimicking metastasis in a newly diagnosed diabetic patient who was later discovered to have an occult sigmoid colon cancer. Case report: A 45-year-old male from Senegal presented to our institution with a three-day complaint of abdominal discomfort refractory to antacids, fevers, malaise and weight loss. Initial laboratory data was significant for mild leukocytosis (WBC: 11,800 / μL) and moderate transaminitis (AST/ALT: 67/105 IU/L). CT scan of the abdomen/pelvis demonstrated a 7.5 cm x 7.0 cm mass in the left hepatic lobe with areas of central necrosis. The sigmoid wall thickening with focal irregularity raised suspicion for a mass lesion (Figure 1).Figure 1Tumor markers were negative. A colonoscopy showed a 5 cm pedunculated polyp in the sigmoid colon, which was removed with hot snare polypectomy (Figure 2). The polyp was a moderately differentiated invasive adenocarcinoma without lymph or vascular invasion and clear margins (Figure 3). A liver biopsy was performed due to persistent temperature spikes and was consistent with a hepatic abscess. Cultures were positive for Klebisella Pneumoniae. The plan was to treat the abscess with antibiotic followed by surgical resection. CT scan of the abdomen/pelvis was obtained on the 21st day after initiation of antibiotics and it demonstrated almost complete resolution of liver lesion.Figure 2Figure 3Patient successfully underwent laparoscopic lower anterior resection of the sigmoid colon. Pathology demonstrates residual tubular adenoma with unremarkable margins and lymph nodes. Discussion: Various etiologies of liver abscess have been proposed. More recently, especially in the eastern countries, studies have reported liver abscesses as a silent manifestation of colon cancer and may represent the initial manifestation of the disease. This type of pyogenic liver abscess has now been reported worldwide and is regarded as a herald sign of colorectal cancers. Other common associations include the diagnosis of diabetes mellitus type II. The sigmoid colon is the most common site of tumor, and Klebsiella Pneumoniae is the most common pathogen isolated in the Eastern Asian countries. The proposed pathogenesis for the above is the destruction of the mucosal barrier and repeated bacterial translocation. Conclusion: In patients with cryptogenic liver abscess, colonoscopy should be performed to rule out an occult colonic lesion.