Aggressive NK-cell leukaemia associated with reactive haemophagocytic syndrome.

We report a case of aggressive NK-cell leukaemia associated with reactive haemophagocytic syndrome in a 29-year-old Korean woman who had several small purpuric patches on both thighs. She also had high fever. Laboratory tests revealed pancytopenia and deranged liver function, and atypical lymphocytes containing toxic granules were detected from peripheral blood and bone marrow. The bone marrow examination showed diffuse histiocytic proliferation with several haemophagocytic macrophages, suggesting an associated reactive haemophagocytic syndrome. Skin biopsy from her thigh lesion demonstrated atypical CD56+ lymphoid cellular infiltrates with angiocentric pattern, and in situ hybridization test for Epstein-Barr virus was positive. Although we treated her with chemotherapy, she died 1 month later.