Precursor natural killer cell leukemia.

Natural killer (NK) cell tumors are a rare and heterogeneous group of disorders. Immature NK cell tumors are less common, and are less recognized and defined than mature NK cell tumors. There is insufficient experience of diagnosis and treatment with immature NK cell tumors, especially in pediatric patients. Here we describe a pediatric patient with precursor NK cell leukemia and review the literature of the previously reported cases in children to further help characterize the diagnosis, treatment, and outcome. (c) 2008 Wiley-Liss, Inc.