Natural killer cell leukemia. An autopsy case.

Abstract

We describe an autopsy case of natural killer cell leukemia. Leukemic cells appeared morphologically as large granular lymphocytes and expressed a restricted natural killer cell phenotype (CD2, CD38, CD56, HLA-DR). Immunogenotypic analysis revealed germline configurations of TCR-beta, TCR-gamma, and JH genes, indicating a non-T-cell or non-B-cell lineage. These features are consistent with natural killer cell leukemia, a recently proposed clinicopathologic entity. Autopsy findings were characterized by an extremely dense infiltration of leukemic cells in most organs, along with destruction of the normal architecture, corresponding to an aggressive clinical course. Hemophagocytic histiocytosis and an absence of chronic inflammatory reactions caused by recurrent infection in our case are different from morphologic features of CD3+ large granular lymphocytic leukemia. No relationship between Epstein-Barr virus and natural killer cell leukemia was observed.