Lack of restricted diffusion in MR imaging as a potential differentiating tool of reactive lymph node in cat scratch disease from lymphoma or abscess

Cat scratch disease is an infection caused by Bartonella Henselae with characteristic presentation of lymphadenopathy. Despite self-limited nature of the disease in most cases, it accounts for many lymph node biopsies performed since its imaging features can mimic lymphoma in appearance, thus requiring additional invasive procedures. Lack of restricted diffusion may be helpful in distinguishing imaging feature of reactive lymph nodes with caseating necrosis seen in cat scratch disease from lymphoma or abscess. We present a case of 12-year-old female, who presented with an arm swelling, MRI of which demonstrated absence of restricted diffusion in the subcutaneous enlarged lymph nodes. She then underwent excisional biopsy with final diagnosis of reactive lymph node and cat scratch disease based on biopsy results and immunoglobulin titer.