In the current study, three patients were diagnosed with HLH, two of whom died despite intensive chemotherapy and intravenous Ig treatment. The mortality rate was significantly higher than for other diseases (p < 0.01). A previous study reported that patients with HLH may not have a typical initial presentation, and that fever persisted for a median of 19 days before the diagnosis was made.12 This may explain why a diagnosis is often delayed. Overall, the reported mortality rate of HLH is around 50%,12, 13 and prompt recognition of the disease is essential to allow for the initiation of appropriate therapy.