Diagnostic challenges related to myeloid/natural killer cells, a variant of myeloblasts.
The authors report herein two diagnostically challenging cases centered on the myeloid/natural killer (myeloid/NK) cells, a variant of myeloblasts, to illustrate the importance of advanced flow cytometric immunophenotyping and an updated understanding of surface markers in hematopoietic malignancies. Myeloid/NK cell acute leukemia is a very rare subtype of leukemia. Although its NK-cell nature is debatable, it represents a variant of leukemia with distinct morphological and immunophenotypical features. The first case is a de novo myeloid/NK-cell acute leukemia with a striking clinical, morphologic and immunophenotypic resemblance to acute promyelocytic leukemia (APL), but which could be distinguished by its CD11a, CD18, CD117 and CD9 expression. This case illustrates the importance of utilizing the APL surrogate surface phenotype of HLA-DR(low), CD11a(low) and CD18(low) by flow cytometric study to rule in/out APL immunophenotypically. In the second case, we show that myeloid/NK-cell blasts can present as a variant of blasts in a preleukemic disease as refractory anemia with excess blasts-1 (RAEB-1), where the blasts were negative for CD34, CD117 and HLA-DR. The recognition of such blast variant is important in appropriately classifying such preleukemic diseases by blast percentage.
Tang
Guilin
G
Department of Pathology, UMass Memorial Medical Center, University of Massachusetts School of Medicine Worcester, MA, USA.
Truong
Franciose
F
Fadare
Oluwole
O
Woda
Bruce
B
Wang
Sa A
SA
Leukemia. 2004 Oct;18(10):1591-8
15343344
Leuk Lymphoma. 2001 Apr;41(3-4):457-60
11378563
Leukemia. 2004 Dec;18(12):2036-8
15483671
Haematologica. 2000 Mar;85(3):322-4
10702827
Blood. 1997 Sep 15;90(6):2417-28
9310493
Ann Hematol. 2001 Jan;80(1):58-61
11233779
Int J Hematol. 1999 Feb;69(2):89-91
10071456
Leuk Res. 2000 Nov;24(11):979-82
11086183
Rinsho Ketsueki. 1995 Jul;36(7):682-6
7563597
Blood. 2002 Dec 1;100(12):3887-96
12393641
Leuk Res. 1992;16(1):43-6
1732669
Cytometry B Clin Cytom. 2004 May;59(1):1-9
15108165
Blood. 1994 Jul 1;84(1):244-55
7517211
Blood. 1994 Oct 15;84(8):2824-5
7522645
Blood. 2000 Dec 15;96(13):4028-38
11110670