Giant hepatic granuloma caused by Bartonella henselae

Challenging Mimickers in the Diagnosis of Sarcoidosis: A Case Study

Sarcoidosis is a systemic granulomatous disease of unknown cause characterized by a wide variety of presentations. Its diagnosis is based on three major criteria: a clinical presentation compatible with sarcoidosis, the presence of non-necrotizing granulomatous inflammation in one or more tissue samples, and the exclusion of alternative causes of granulomatous disease. Many conditions may mimic a sarcoid-like granulomatous reaction. These conditions include infections, neoplasms, immunodeficiencies, and drug-induced diseases. Moreover, patients with sarcoidosis are at risk of developing opportunistic infections or lymphoma. Reliably confirming the diagnosis of sarcoidosis and better identifying new events are major clinical problems in daily practice. To address such issues, we present seven emblematic cases, seen in our department, over a ten-year period along with a literature review about case reports of conditions misdiagnosed as sarcoidosis.

Granulomatous hepatitis due to Bartonella henselae infection in an immunocompetent patient

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.

An unusual outcome in a child with hepatosplenic cat-scratch disease

Typical cat-scratch disease (Bartonella henselae infection) in an immunocompetent child is usually associated with a history of scratch, bite or intimate contact with a cat. Most patients develop a non-tender papule in the scratch line after three to ten days. This may persist for only a few days or as long as two to three weeks. During the next two weeks or more, regional lymph nodes that drain the area gradually enlarge and then slowly resolve in more than 10% of patients. The nodes develop overlying erythema and may suppurate. Atypical forms of cat-scratch disease occur in a minority of cases and are characterized by ocular or neurological manifestations, hepatosplenic involvement, vertebral osteomyelitis, endocarditis etc. Immunocompromised individuals with B. henselae infection may develop bacillary angiomatosis, bacillary peliosis, and relapsing bacteremia. There have been several reports of hepatosplenic granulomas caused by B. henselae in immunocompetent children. We report a case of a 6-year-old boy with the hepatosplenic form of cat-scratch disease. Despite early diagnosis and long-term antimicrobial treatment, splenectomy could not be avoided.

Granulomatous liver disease and cholestasis

Development of hepatic granulomas, especially those located within portal tracts, is associated with injury to septal and interlobular bile ducts. Dysfunction of the bile ducts in turn leads to cholestasis,and ongoing damage by the granulomatous inflammation eventually results in ductopenia. A multitude of causes of hepatic granulomas have been described over the last few decades. Diligent and prioritized search for cause of hepatic granulomas should proceed within the environmental and epidemiologic context of a given patient. The therapeutic approaches, including amelioration of the cholestatic syndrome, are often determined by successful identification of specific etiologic factors causing the granulomas in the liver.

Detection of Bartonella henselae and Bartonella clarridgeiae DNA in hepatic specimens from two dogs with hepatic disease

A 4-year-old Basset Hound and a 6-year-old Doberman Pinscher were referred for diagnostic evaluation following documentation of persistently increased hepatic enzyme activities and hepatic dysfunction. Histologic evaluation of hepatic biopsy specimens from the 2 dogs revealed granulomatous hepatitis in the Basset Hound and lymphocytic hepatitis with fibrosis and copper accumulation in the Doberman Pinscher. No etiologic agents were identified histologically. Bartonella henselae DNA was subsequently amplified from hepatic tissue from the Basset Hound and Bartonella clarridgeiae was amplified from hepatic tissue from the Doberman Pinscher. Amplification was performed with a polymerase chain reaction assay incorporating primers that target a portion of the 16S-23S rRNA intergenic spacer region. Both dogs were treated with azithromycin, in combination with a variety of other medications and herbal treatments, and improved clinically. Identification of Bartonella DNA in these dogs indicates the need for future prospective studies to determine the clinical relevance of Bartonella spp infection in dogs with hepatic disease.