Secondary myeloid/natural killer cell acute leukemia following T-cell lymphoma.

A 56-year-old woman was treated with combination chemotherapy and radiation therapy for peripheral T-cell lymphoma. Following complete remission for a period of 6 months, she returned again with marked leukocytosis. Leukemic cells were characterized by scanty cytoplasm with fine azurophilic granules, and were highly positive for myeloperoxidase and sudan black-B. Immunophenotypic analysis revealed that blast cells were positive for myeloid antigens (CD13, CD33), and natural killer (NK) cell antigen (CD56), but negative for T-cell antigens (CD2, CD5, CD7), B-cell antigens (CD19, CD20), CD34, and HLA-DR. The case was diagnosed as secondary myeloid/NK cell acute leukemia following non-Hodgkin's lymphoma. Despite aggressive chemotherapy against leukemia, she died of multiorgan failure 7 months following onset of leukemia. We present, to the best of our knowledge, the first published report of what seems to be a secondary myeloid/NK cell acute leukemia following T-cell lymphoma.