2308 A Rare Cause of Pyogenic Liver Abscess

Abstract

INTRODUCTION: Pyogenic liver abscess (PLA) is a rare clinical entity with an annual incidence of 0.5 to 0.8 percent. While these infections are typically polymicrobial, Staphylococcus aureus has also rarely been implicated. Here, we report a case of a community acquired Methicillin resistant Staphylococcus aureus (MRSA) hepatic abscess, which responded to clindamycin. CASE DESCRIPTION/METHODS: A 67-year-old man with history of untreated chronic hepatitis C and intranasal heroin abuse presented with shortness of breath, right sided pleuritic chest pain and generalized abdominal discomfort. Physical examination was notable for skin pallor, cachexia and right upper quadrant tenderness. Laboratory tests revealed albumin 2.6 g/dl (ref: 3.8-5.2), total bilirubin 2.8 mg/dl (ref: 0.2-1.2), direct bilirubin 1.3 mg/dl (ref: 0.0-0.2), hemoglobin 6 g/dl (ref: 12.9-16.8) and no leukocytosis. Computed tomography (CT) scan of abdomen demonstrated an ill-defined right hepatic lobe mass concerning for hepatocellular carcinoma (HCC). A triple phase CT scan revealed liver cirrhosis and a complex cystic solid mass 10 × 5 × 6 cm in size, raising suspicion for HCC versus a hepatic abscess (Figure 1). Biopsy yielded pus and a pig tail catheter was placed. He was started on ampicillin-sulbactam for possible polymicrobial hepatic abscess, but it was later switched to IV Vancomycin when the cultures grew MRSA (Figure 2). On further testing, no source of infection was identified. He left against medical advice and was discharged with four weeks of clindamycin. A repeat CT scan five months later showed resolution of the hepatic abscess and the drain was removed (Figure 3). DISCUSSION: Community acquired MRSA is an uncommon cause of PLA with only a few cases reported in literature. The source of infection if identified is usually cutaneous or intraabdominal. We could not identify any infectious foci in our patient. Radiographic appearance of multi-loculated hepatic abscess can masquerade HCC, as in our patient, warranting further diagnostic workup. The mainstay of treatment is drainage and prolonged antibiotic therapy. Intravenous vancomycin is the drug of choice. Linezolid has been used as an oral alternative previously, but our patient responded well to clindamycin, suggesting that it could be a less expensive but equally efficacious choice. Surgical intervention maybe necessary if there is no improvement after 4 to 7 days of percutaneous drainage or if there is viscous pus in thick-walled or multilobulated abscesses.