Pyogenic Liver Abscess with Streptococcus mitis as Causative Agent

Abstract

Pyogenic liver abscesses caused by Streptococcus viridans is a rare etiology and only two cases have been reported in the literature. We report a 40-year-old male who presented with intermittent fevers, abdominal pain, and a right hepatic lobe mass on abdominal ultrasound and abdominal computed tomography. Blood tests showed elevated liver enzymes. The patient underwent drainage of the abscess. Culture of the purulent material obtained yielded Streptococcus mitis as the causative agent. Treatment of pyogenic liver abscesses is crucial and involves invasive approaches such as drainage. In addition, bacteriological studies must be performed as well to isolate the specific agent and provide appropriate antimicrobial therapy. A 40-year-old male presented with a three week history of intermittent fevers, generalized fatigue, abdominal pain, and upper respiratory symptoms. The patient was diagnosed with strep throat one month prior to his admission to the hospital. He was given a ten-day course of Penicillin and had initial resolution of symptoms. Soon after, the fevers recurred along with chills and night sweats. He also complained of diffuse intermittent abdominal pain greatest in the right upper quadrant. The physical examination was remarkable for scleral icterus and tenderness to palpation in the right upper quadrant. Investigations showed a white cell count of 15.2 K/uL, neutrophils 85%, aspartate aminotransferase 69 IU/L, alanine transaminase 102 IU/L, alkaline phosphatase 358 IU/L, total bilirubin 1.4 mg/dL, direct bilirubin 1.0 mg/dL. CEA, CA 19-9, and AFP tumor markers were negative. Blood cultures were negative. Abdominal ultrasound revealed an irregular right hepatic lobe mass predominantly hypoechoic but contained some solid appearing internal echogenic components. The mass measured 5.4 x 5.1 x 4.9 centimeters. Abdominal computed tomography confirmed the presence of a right hepatic lobe mass occupying predominantly hepatic segment six with slight extension into hepatic segment seven. The patient then underwent percutaneous computed tomography guided abscess drainage with placement of a drainage catheter. There was approximately 50 milliliters of purulent material, bloody in nature, aspirated from the mass which was sent for culture. The abscess culture grew Streptococcus mitis sensitive to quinolones. The patient was placed on moxifloxacin therapy for a total of two weeks and had the drainage catheter removed after two weeks as drainage was minimal.Figure 1Figure 2