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.

Case presentation: 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.

Conclusion: 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.

Figure 1

Abdominal CT image demonstrating a large mass lesion in the right hepatic lobe.

Figure 2

The right partial hepatectomy shows florid necrotizing granulomatous inflammation for a peudotumorous mass (Figure 2, hematoxylin and eosin 100×). Necrotizing granulomatous inflammation with giant cells and characteristic palisading histiocytes.

Figure 3

The right partial hepatectomy shows florid necrotizing granulomatous inflammation for a peudotumorous mass. Necrotizing granulomatous inflammation with giant cells and characteristic palisading histiocytes (Figure 3, hematoxylin and eosin 400×).

Figure 4

Repeat abdominal CT after initial hepatic resection. Several new, low-attenuation lesions are present in the right hepatic lobe. Similar, smaller lesions were present in the left hepatic lobe (not shown).

Figure 5

PCR results targeting the Bartonella 16S-23S rRNA intergenic spacer region using primers 325-1000 and primers 425-1100 (top row) and Bartonella koehlerae specific primers (bottom row). With primers 325-1000, amplicons were obtained in lanes 1-3 from the resected liver lobe (pre-antibiotic treatment) but not in Lanes 4-5 (post-treatment liver biopsy). With primers 425-1000, single amplicons were obtained in the pre- (Lane 2) and post-treatment (Lane 5) liver samples. By DNA sequencing, all amplicons corresponded to a 16S-23S strain of B. henselae. No amplicons were obtained with the B. koehlerae primer set. RC = DNA extraction control, lane, BH = B. henselae (Houston I strain), PO = PCR negative control, M = Kb DNA ladder.