Gastrointestinal Variant of Lemierre Syndrome due to Fusobacterium nucleatum: A Case Report

Abstract

Introduction: Pyogenic liver abscess is a noteworthy health concern in North America, characterized by a mortality rate ranging from 2 to 12%. This condition is often polymicrobial, with Streptococcus species and Escherichia coli as the predominant causal pathogens in Western countries. Fusobacterium species, typically commensals of gastrointestinal, genital, and oral flora, have been implicated in the rare formation of tonsillar abscesses and Lemierre syndrome, including its gastrointestinal variant known as pylephlebitis.

Case presentation: We present the case of an immunocompetent male with a 2-week history of abdominal distention and pain. Abdominal magnetic resonance imaging revealed multiseptated cystic hepatic masses and portal vein thrombosis. A subsequent liver biopsy confirmed Fusobacterium nucleatum etiology. The patient was initiated on intravenous cefepime and oral metronidazole antibiotics. Unfortunately, the patient succumbed to cardiac arrest before a final diagnosis could be established.

Conclusion: Fusobacterium species-associated liver abscess, coupled with the rare gastrointestinal variant of Lemierre syndrome (pylephlebitis), poses a significant mortality risk. This case underscores the rarity and clinical challenges associated with these conditions. Increased awareness among clinicians is crucial for early diagnosis and prompt intervention, potentially improving outcomes in such cases.

Keywords: Abscess; Fusobacterium; Liver; Liver abscess; Pyogenic liver abcess.

Fig. 1.

a Transverse CT image of the abdomen taken 6 months prior to presentation. b Transverse CT image of the abdomen demonstrating multiple lesions throughout the grossly enlarged liver indicated by black arrows and hypoattenuation indicating thrombosis within the portal vein showcased by white arrow.

Fig. 2.

a MRI of the abdomen, showing numerous lesions throughout the grossly enlarged liver by white arrowheads. b White arrows point to an area of increased attenuation within the portal vein indicative of thrombus.

Fig. 3.

Low (×40) H&E image of abscess material with granulation tissue (a) and high magnification (×200) H&E image of adjacent liver parenchyma with neutrophilic infiltrate (b).