An unusual case of CD4+ CD7+ CD56+ acute leukemia with overlapping features of type 2 dendritic cell (DC2) and myeloid/NK cell precursor acute leukemia.
Type 2 dendritic cell (DC2) acute leukemia has been recently described. We report here an unusual case of a 17-yr-old adolescent with overlapping features of DC2 and myeloid/NK cell precursor acute leukemia as defined by Suzuki et al. The patient presented with lymphadenopathy and hepatosplenomegaly without extranodal manifestations in skin or elsewhere. The morphologic, cytochemical and immunophenotypic features were compatible with those described in DC2 acute leukemia, with co-expression of CD4, CD56 and CD123 antigens. The novel markers BDCA-4 and BDCA-2 considered specific for DC2s were co-expressed. However, bright CD7 positivity along with a dim expression of CD33 (57%) and CD117 (27%) were also noted. Additionally, there was bright expression of NG2 monoclonal antibody 7.1, a frequent finding in myeloid/NK cell precursor acute leukemia. The interpretation of the immunophenotypic profile leads to the hypothesis on the existence of borderline cases between DC2 and myeloid/NK cell precursor acute leukemia. Still, other hypotheses can not be overlooked, such as the possibility for a kind of variant monoblastic leukemia or of another rare entity of acute unclassified leukemia.
Anargyrou
K
K
First Department of Internal Medicine, Laikon General Hospital, University of Athens, Athens, Greece.
Paterakis
G
G
Boutsis
D
D
Politou
M
M
Papadhimitriou
S I
SI
Siakandaris
M
M
Vassiliadis
J
J
Androulakis
A
A
Meletis
J
J
Rombos
J
J
Tassiopoulou
A
A
Vaiopoulos
G
G
D000293:Adolescent; D015703:Antigens, CD / Q000096:biosynthesis; D019011:Antigens, CD7 / Q000096:biosynthesis*; D015214:Antigens, Differentiation, Myelomonocytic / Q000096:biosynthesis; D000954:Antigens, Surface / Q000097:blood; D001854:Bone Marrow Cells; D015704:CD4 Antigens / Q000096:biosynthesis*; D019002:CD56 Antigen / Q000096:biosynthesis*; D003713:Dendritic Cells / Q000166:cytology*; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000166:cytology*; D037181:Lectins, C-Type / Q000097:blood; D007938:Leukemia / Q000097:blood* / Q000378:metabolism*; D015470:Leukemia, Myeloid, Acute / Q000097:blood; D017493:Leukocyte Common Antigens / Q000096:biosynthesis; D008297:Male; D008562:Membrane Glycoproteins; D019009:Proto-Oncogene Proteins c-kit / Q000096:biosynthesis; D011971:Receptors, Immunologic; D063268:Sialic Acid Binding Ig-like Lectin 3
D015703:Antigens, CD; D019011:Antigens, CD7; D015214:Antigens, Differentiation, Myelomonocytic; D000954:Antigens, Surface; C571163:CD33 protein, human; D015704:CD4 Antigens; D019002:CD56 Antigen; C443299:CLEC4C protein, human; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; D063268:Sialic Acid Binding Ig-like Lectin 3; C478196:blood dendritic cell antigen 4, human; D019009:Proto-Oncogene Proteins c-kit; D017493:Leukocyte Common Antigens