Cat scratch disease in two children presenting with fever of unknown origin: imaging features and association with a new causative agent, Rochalimaea henselae.

To report the clinical course, imaging findings, and method of diagnosis of two patients with systemic manifestations of cat scratch disease, presenting with fever of unknown origin.Case study.Two children with fever of unknown origin who had multiple lesions in the liver and spleen, shown on ultrasound, computed tomography, and magnetic resonance imaging. Initial diagnoses were Kawasaki disease (case 1) and metastatic neuroblastoma (case 2).Biopsy material showed granulomatous hepatitis in both patients. The diagnoses were confirmed by positive assays for Rochalimaea henselae, currently thought to be the causative agent of cat scratch disease.Cat scratch disease presenting as fever of unknown origin is now well described and can be more readily diagnosed because of the availability of new serologic assays, as well as polymerase chain reaction assays for R henselae DNA in tissue specimens.