Favorable outcome in a child with EBV-negative aggressive NK cell leukemia.

Aggressive natural killer cell leukemia (ANKL) is a rare malignant disorder of mature NK cells frequently associated with Epstein-Barr virus (EBV). This malignancy is typically treated with intensive remission induction chemotherapy followed by allogeneic hematopoietic stem cell transplantation (HSCT). EBV-negative ANKL and childhood ANKL, however, are not well defined and the optimal therapeutic strategy in these cases is poorly understood. Here, we present a unique pediatric EBV-negative ANKL patient who achieved a successful treatment outcome after intensified ALL type chemotherapy without allogeneic HSCT.