Patient 1: A.T.
A 2-year-old African-American male presented with fevers and severe sepsis secondary to Streptococcus pyogenes bacteremia. Initial studies showed pancytopenia and hyperferritinemia which raised concerns for HLH and the patient was started on a 5-day course of dexamethasone. Evaluation for malignancy was attempted, but the patient became hemodynamically unstable with positioning during bone marrow biopsy and an inadequate sample was obtained with inconclusive results. Peripheral flow cytometry did not show presence of immature blasts. He met criteria for HLH and was treated with dexamethasone and etoposide per HLH-2004 and responded well without complications. However, 7 months after initial presentation, he presented with pancytopenia and was diagnosed with B-ALL. He was treated per COG-AALL1731 with persistent disease throughout induction and consolidation, which required the addition of blinatumomab. [3] His case raised the concern for an incomplete diagnostic approach during his initial HLH diagnosis that resulted in a false negative result that delayed the diagnosis of an underlying malignancy and partial treatment with dexamethasone.