The histologic spectrum of hepatic cat scratch disease - A series of six cases with confirmed Bartonella henselae infection

Cat scratch disease (CSD), a common cause of regional lymphadenitis, has been linked to Bartonella henselae infection. Although rare, dissemination with hepatic involvement has been documented. Six cases of hepatic CSD were retrieved and probed for B. henselae DNA. Hematoxylin-eosin, trichrome, methenamine silver, Gram, Ziehl-Neelsen, and Warthin-Starry stained slides were reviewed by all authors, and the histologic findings were recorded. B. henselae infection was confirmed in all cases using combined polymerase chain reaction and Southern blot methods. All biopsies contained multiple granulomas, many with characteristic stellate abscesses surrounded by three distinct zones: an inner layer of palisading histiocytes, an intermediate lymphocytic rim, and an outermost zone of fibrosis. One case had noncaseating granulomas with prominent giant cells. Warthin-Starry stains were positive in two. The surrounding parenchyma in all cases contained lymphocytic infiltrates within expanded fibrotic portal triads and adjacent dilated sinusoids. There is a distinct spectrum of histologic changes in hepatic CSD. Although the unit lesion is granulomatous, the organization varies markedly. All cases show predictable nonspecific surrounding parenchymal changes. When multiple hepatic lesions are found in patients with constitutional symptoms suggesting an infectious illness, CSD should be included in the differential diagnosis.