You are examining a 5-year-old child who has had recurrent f…

You are examining a 5-year-old child who has had recurrent fevers, bone pain, and a recent loss of weight. The physical exam reveals scattered petechiae, lymphadenopathy, and bruising. A complete blood count shows thrombocytopenia, anemia, and an elevated white cell blood count. Based on findings, you are concerned for: