S. Kawano et al., NOVEL LEUKEMIC LYMPHOMA WITH PROBABLE DERIVATION FROM IMMATURE STAGE OF NATURAL-KILLER (NK) LINEAGE IN AN AGED PATIENT, Hematological oncology, 13(1), 1995, pp. 1-11
A 66-year-old male patient was admitted with dyspnea; physical examina
tion revealed petechiae and systemic lymphadenopathy. Laboratory findi
ngs showed leukemia. The blasts in the peripheral blood were negative
for cytochemical myeloperoxidase, and had condensed nuclear chromatin
with a nucleolus. The histological diagnosis of the biopsied neck lymp
h node was lymphoblastic lymphoma. The leukemia cells expressed CD2, C
D6, CD7, CD13(low), CD56, beta chain of IL-2 receptor(low) (IL-2R beta
), and HLA-DR antigens, but not other pan-T (CD5, CD3, CD4, and CD8);
pan-B (CD10, CD19, CD20, and CD24); natural killer (NK) (CD16, CD57);
or myeloid (CD33) antigens. Electronmicroscopy revealed convoluted nuc
lei with conspicuous nucleoli and peripherally condensed heterochromat
in. Membrane-bound granules containing an electron dense matrix were o
bserved in the cytoplasm, indicating the NK cell nature of the neoplas
tic cells. While terminal deoxynucleotidyl transferase (TdT) and cytop
lasmic CD3 were not detected by immunofluorescence on fixed smears, No
rthern blot analysis revealed the gene expression of CD3 epsilon, CD3
zeta, and TdT. Gene rearrangement analysis revealed that the beta, gam
ma, and delta chains of T-cell receptor (TCR) and immunoglobulin heavy
chain (IgH) were of germline genotype. While the overall interpretati
on of the phenotype and genotype was difficult, the derivation of an i
mmature stage of NK lineage was strongly suggested, based predominantl
y on the electronmicroscopic features. Despite initially successful ch
emotherapy, the patient died 14 months after initial presentation.