[Clinicopathologic features of aggressive natural killer cell leukemia].
ABSTRACT To study the clinicopathologic features of aggressive natural killer cell leukemia (ANKL).
The clinical and pathologic features were analyzed in 10 patients with ANKL. The complete blood count, peripheral blood smears, bone marrow aspirates and bone marrow biopsies were studied. Immunophenotypic analysis was carried out by flow cytometry and immunohistochemistry. T-cell receptor (TCR) γ gene rearrangement was studied by PCR method.
The most frequent hematologic abnormalities observed were anemia (7 cases) and thrombocytopenia (9 cases). Large granular lymphocytes were found on peripheral blood smears of 6 patients. In bone marrow aspirates, lymphocytosis (> 20.0%) was demonstrated in 8 cases and large granular lymphocytes in 6 cases. Bone marrow biopsies revealed various degrees of neoplastic infiltration, as follows: mild (5 cases), moderate (3 cases) and severe (2 cases). The neoplastic cells were mainly interstitial in distribution in 8 cases and diffuse in 2 cases. Hemophagocytosis was observed in 4 cases. Flow cytometry showed CD2+ sCD3- CD4- CD56+ CD57- in all cases, CD7+ in 9 cases, CD16+ in 5 cases, CD8+ in 4 cases and CD5+ in 1 case. Immunohistochemistry performed in 8 cases showed the following results: cCD3+ in 4 cases, CD56+ in 6 cases, TIA-1+ in 6 cases, granzyme B+ in 4 cases and perforin+ in 2 cases. PCR study revealed germline TCRγ gene configuration in all cases.
ANKL is a highly aggressive NK cell-derived lymphoid neoplasm. Comprehensive morphologic, immunophenotypic and molecular analysis are essential in arriving at a correct diagnosis. ANKL needs to be distinguished from other types of NK-cell and T-cell lymphomas.
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ABSTRACT: Mature natural killer (NK) cell neoplasms are classified by the World Health Organization into NK/T cell lymphoma, nasal type (NKTCL), aggressive NK-cell leukemia (ANKCL) and chronic lymphoproliferative disorders of NK-cells, the latter being considered provisionally. NKTCL and ANKCL are rare diseases, with higher prevalence in Asia, Central and South America. Most NKTCL present extranodal, as destructive tumor affecting the nose and upper aerodigestive tract (nasal NKTCL) or any organ or tissue (extranasal NKTCL) whereas ANKCL manifests as a systemic disease with multiorgan involvement and naturally evolutes to death in a few weeks. The histopathological hallmark of these aggressive NK-cell tumors is a polymorphic neoplastic infiltrate with angiocentricity, angiodestruction and tissue necrosis. The tumor cells have cytoplasmatic azurophilic granules and usually show a CD45+bright, CD2+, sCD3-, cytCD3epsilon+, CD56+bright, CD16-/+, cytotoxic granules molecules+ phenotype. T-cell receptor genes are in germ-line configuration. Epstein-Barr virus (EBV) -encoded membrane proteins and early region EBV RNA are usually detected on lymphoma cells, with a pattern suggestive of a latent viral infection type II. Complex chromosomal abnormalities are frequent and loss of chromosomes 6q, 11q, 13q, and 17p are recurrent aberrations. The rarity of the NK-cell tumors limits our ability to standardize the procedures for the diagnosis and clinical management and efforts should be made to encourage multi-institutional registries.Orphanet Journal of Rare Diseases 07/2013; 8(1):95. · 4.32 Impact Factor