2478 Approach to a Foreign Body (Fish Bone) Resulting in a Liver Abscess With Antibiotic-Evading Filamentation of Bacterial Organisms Resembling Fungal Hyphae

Abstract

INTRODUCTION: Foreign bodies that are ingested may migrate from the gastrointestinal (GI) tract into different organs of the body and cause a variety of clinical manifestations including fever of unknown origin. In this vignette we describe the case of a transmural fish bone migration from the stomach to the liver causing a recurrent liver abscess. CASE DESCRIPTION/METHODS: A 76 year old Caucasian male with a past medical history of hypertension presented to the hospital with a left liver lobe abscess that was aspirated six years ago. All cultures at that time were negative and apparently resolved with antibiotics. About two months prior to his hospital admission, he started developing subjective fevers and malaise, with CT Scan of the abdomen showing a possible liver mass in the left lobe. He underwent a liver biopsy of this lesion that showed multiple caseating granulomas. Infectious work up was negative. Despite broad spectrum antibiotics, the patient continued with low grade fevers. Pancultures were negative and a left liver lobectomy and cholecystectomy was pefomed. CT imaging of the liver showed a multiloculated 7.2 cm lesion in the left lobe of the liver consistent with an abscess, with a linear foreign body which extended from the stomach into the left lobe liver lesion (Figure 1). During surgery, the foreign body was identified and removed. Surgical histology of the foreign body showed bone fragments lined by osteocytes and calcifications, which was identified as a “fish bone.” Furthermore, the left liver lobe showed prominent granulomatous inflammation with necrosis and microabscesses with no evidence of malignancy. Special stain GMS-F was positive for filamentous organisms that most closely resembled nocardia or streptomyces (Figure 2). DISCUSSION: This is the first case report showing filamentation of bacteria resembling a fungal infection causing a liver abscess due to a fish bone that penetrated the left lobe of the liver. Filamentation is a bacterial defense mechanism against eradication by antibiotics, which explains failure of resolution of the infection with antimicrobials. Studies have reported incomplete bacterial replication leading to the appearance of filamentation resembling fungal species. This phenomenon should be considered by clinicians when treating challenging liver foreign body abscesses.