Chronic T-cell lymphoproliferative disease expressing natural killer cell receptors: clinicopathological and molecular features

The frequency and clinicopathological significance of the expression of nat ural killer cell receptors (NKRs) in T-cell malignancies remain undefined. A 71-year-old man presented with leukocytosis, generalized lymphoadenopathy , and hepatosplenomegaly. Bone marrow and lymph node biopsies showed a T-ce ll lymphoproliferative disease expressing NKRs (CD2(+), CD3(+), CD4(+), CD5 (+), CD7(+), CD8(-), CD56(-), CD94(+). CD158a(+), CD158b(+), CD161(+), p70( -), TCR alpha beta (+), TCR gamma delta (-), TIA-1(-)). An abnormal clone. 46,Y,add(X)(p14),der(1)t(1:6)(p33 p21),t(7:12)(p10;q10), was found on conve ntional karyotyping. Comparative genomic hybridization confirmed these find ings, and showed a deletion of 12p that was not apparent on karyotyping. Cl inically, the disease remained indolent and responded transiently to purine analogs but not to intensive chemotherapy. Peripheral T-cell lymphoprolife rative disease of CD4(+)alpha beta +NKR+ phenotype is hitherto undescribed. The issues of whether this case was derived from transformation of a rare T-cell subtype or represented aberrant T-cell expression of NK-cell antigen s, and the clinicopathologic significance of these T-cell neoplasms warrant further studies. (C) 2001 Elsevier Science Inc. All rights reserved.