title: Granulomatous hepatitis due to Bartonella henselae infection in an immunocompetent patient.
abstract: BACKGROUND
  Bartonella henselae (B. henselae) is considered a rare cause of granulomatous hepatitis. Due to the fastidious growth characteristics of the bacteria, the limited sensitivity of histopathological stains, and the non-specific histological findings on liver biopsy, the diagnosis of hepatic bartonellosis can be difficult to establish. Furthermore, the optimal treatment of established hepatic bartonellosis remains controversial.
  
  
  METHODS
  We present a case of hepatic bartonellosis in an immunocompetent woman who presented with right upper quadrant pain and a five cm right hepatic lobe mass on CT scan. The patient underwent a right hepatic lobectomy. Surgical pathology revealed florid necrotizing granulomatous hepatitis, favoring an infectious etiology. Despite extensive histological and serological evaluation a definitive diagnosis was not established initially. Thirteen months after initial presentation, hepatic bartonellosis was diagnosed by PCR studies from surgically excised liver tissue. Interestingly, the hepatic granulomas persisted and Bartonella henselae was isolated from the patient's enriched blood culture after several courses of antibiotic therapy.
  
  
  CONCLUSIONS
  The diagnosis of hepatic bartonellosis is exceedingly difficult to establish and requires a high degree of clinical suspicion. Recently developed, PCR-based approaches may be required in select patients to make the diagnosis. The optimal antimicrobial therapy for hepatic bartonellosis has not been established, and close follow-up is needed to ensure successful eradication of the infection.
authors.affiliation: Department of Internal Medicine, Division of Gastroenterology, Hepatology and Nutrition, Loyola University Medical Center, 2160 South First Avenue, Maywood, IL 60153, USA. tvanderheyden@lumc.edu
authors.forename: Thomas R
authors.initials: TR
authors.lastname: VanderHeyden
authors.forename: Sherri L
authors.initials: SL
authors.lastname: Yong
authors.forename: Edward B
authors.initials: EB
authors.lastname: Breitschwerdt
authors.forename: Ricardo G
authors.initials: RG
authors.lastname: Maggi
authors.forename: Amanda R
authors.initials: AR
authors.lastname: Mihalik
authors.forename: Jorge P
authors.initials: JP
authors.lastname: Parada
authors.forename: Claus J
authors.initials: CJ
authors.lastname: Fimmel
mesh_terms: D000328:Adult; D001474:Bartonella Infections / Q000175:diagnosis* / Q000382:microbiology / Q000473:pathology / Q000601:surgery; D018416:Bartonella henselae / Q000302:isolation & purification*; D001769:Blood / Q000382:microbiology; D005260:Female; D006099:Granuloma / Q000382:microbiology / Q000473:pathology*; D006505:Hepatitis / Q000175:diagnosis* / Q000382:microbiology / Q000473:pathology / Q000601:surgery; D006651:Histocytochemistry; D006801:Humans; D008099:Liver / Q000382:microbiology / Q000473:pathology*; D008853:Microscopy; D016133:Polymerase Chain Reaction; D011860:Radiography, Abdominal; D014057:Tomography, X-Ray Computed