Blastic natural killer cell (NK-cell) lymphomas or leukemias can be diagnosed if certain findings are present.


Histology: immature mononuclear cells in tissue and lymphoblast-like in bone marrow or blood. Areas of lymphoma show a monotonous proliferation with diffuse infiltration into T-zone areas.



(1) CD56 positive

(2) negative for surface CD3 (cytoplasmic CD3 may be present)

(3) negative for T-cell markers: CD8, T cell receptor (TCR) gene

(4) negative for B-cell markers: CD20, surface immunoglobulins

(5) negative for myelomonocytic markers: CD13, CD14, CD15, CD25, CD33, myeloperoxidase

(6) often positive for CD4, CD7, and/or CD43

(7) often positive for HLA-DR

(8) may be positive for TdT and/or CD34

(9) may be positive for CD16 (an NK cell marker)


For diagnosis the cells must show >= 1 NK cell antigen and be negative for all B-cell, T-cell, and myelomonocytic antigens.


Criteria for the diagnosis of leukemia - one of the following:

(1) > 30% tumor cells in bone marrow

(2) > 30% tumor cells in peripheral blood


If the proliferation was not leukemia, then it was termed lymphomatous.


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