Altaf et al. Journal of Medical Case Reports 2012, 6:141 http://www.jmedicalcasereports.com/content/6/1/141 Page 4 of 6 a c b d CD20 CD3 EBER Figure 2 Lymph node biopsy showing atypical diffuse large B-cell lymphoma cells positive for CD20, immunohistochemistry showing negativity for CD3, and in situ hybridization using Epstein-Barr virus encoded probes showing diffuse positivity for the virus. presentation. Immunosuppression controlled the cyto- kine storm secondary to EBV; however, our patient had clear clinical and imaging evidence of lymphoma by the time she completed the induction phase for her HLH. Malignancy-associated HLH may develop before the diagnosis of cancer or during the treatment phase. It is mostly described in association with T-cell or NK cell lymphomas or leukemias [8-10]. Hemophagocytosis and B- cell lymphomas are described in the majority of Asian patients and it is hypothesized that there may be genetic and environmental factors pertinent to this population which may be responsible for the transformation to B-cell lymphoma [11]. Hence, it is recommended that, in children with systemic HLH, a diagnosis of non-Hodgkin lymphoma Figure 3 Positron emission tomography scan at diagnosis of lymphoma and at completion of therapy.