In early November 2014 an 18-year-old man presented to our department with fever above 40 C, headaches, night sweats, and diffuse arthralgia for the last two weeks. Suspecting a bacterial infection with an unknown focus, he had been treated with ampicillin/sulbactam in a secondary care hospital for two weeks.
The patient reported having been on a one-week holiday in Turkey three months ago. At the time of admission he was doing his military service. Before military service he lived at his parents' farm, where several different animal species are kept, including cattle, chicken, and cats. The full medical examination showed no abnormalities except bilateral cervical lymphadenopathy.
Laboratory investigations revealed markedly elevated C-reactive protein (CRP) of 11.41 mg/dL on day of admission. White blood count was within the normal range with 9.21 G/L. Differential blood count showed a decrease in lymphocyte count of 16%.
Antimicrobial therapy was stopped and serial blood cultures, serologies for Entamoeba, Francisella tularensis, Brucella spp., and fungal, bacterial, and viral broad-spectrum PCRs were performed. All results were negative and did not provide evidence for a specific infectious pathogen. Similarly, QuantiFeron-TB test for Mycobacterium tuberculosis showed negative results and screening for autoimmune antibodies including rheumatoid factor, c-ANCA, and p-ANCA did not indicate autoimmune disease.
Due to the patient's symptoms, such as fever and lymphadenopathy, and his inconclusive laboratory findings, a CT scan was performed, which showed multiple hypodense hepatic and splenic lesions; the largest is 2 cm in diameter (Figure 1). Furthermore subchondral sclerosis and erosion of the ventral thoracic spine were shown with maximal affection of the seventh vertebral body.
Given the ambiguous structure of the spine, a MRI was done, confirming a ventral base plate fracture of vertebral body 7 with reduction in height of 20% and bone marrow edema (Figures 2, 3, and 4). The lesions were suggestive for an underlying infectious origin as were the hepatosplenic lesions.
Due to the radiological appearance, the stagnant infection parameters with negative serologies for Francisella tularensis, Brucella spp., Entamoeba, and blood cultures for common infectious pathogens, and the patient's history of residency on a farm with cats, serologic testing for B. henselae was performed. IgM (1 : 1000) and IgG (1 : 10.000) antibodies for B. henselae were highly elevated. Consequently, according to recently published guidelines, the diagnosis of an atypical presentation of visceral cat scratch disease with bone involvement was established.
Consequently, regarding a histopathological examination of a cervical lymph node, we decided not to take a biopsy, to avoid potential risks involved with this procedure, especially since diagnosis could be established with the patient's clinical presentation, history, laboratory findings, and serology. A PCR for Bartonella henselae could not be performed, as this test is not available in our hospital.