Intracranial nasal natural killer/T-cell lymphoma: immunopathologically-confirmed case and review of literature.

Advances in immunophenotypic profiling now permit characterization of natural killer/T-cell (NK/T-cell) lymphoma as distinct from other extranodal T- and B-cell Non-Hodgkin's lymphomas. NK/T-cell lymphoma presents most commonly in the nasal cavity. Disease progression to the central nervous system (CNS) is a rare phenomenon. We present here, to our knowledge, the first immunophenotypically-confirmed case of direct extension of nasal NK/T-cell lymphoma to the brain. In addition, we review the literature with respect to NK/T-cell lymphoma metastasis to the CNS. The overall prevalence of NK/T-cell lymphoma CNS metastasis is less than 3%. Although rare, CNS invasion portends a poor prognosis, emphasizing the importance of early and accurate immunophenotype profiling and the need for novel, aggressive therapy.