Korean J Clin Pathol.  1998 Mar;18(1):42-45.

A Case of Acute Myeloid Leukemia with an Unusual Phenotype

• Kim MH
• Jeong SH

Abstract

We introduce an unusual case of acute myeloid leukemia (AML) showing strong myeloperoxidase (MPO) positivity without any lineage-specific cell surface marker expression, i.e. myelomonocytic antigens CD13, CD14, CD15 and CD33; or B-lymphoid antigens CD10, CD19, CD20, CD22 and surface immunoglobulin; or T-lymphoid antigens CD2, CD3, CD5 and CD7. The case was morphologically AML with maturation (FAB M2) and the cytogenetic study showed t (8; 21) (q22; q22) and missing Y. But Immunophenotypic studies by flow cytometry showed positive reaction ony for CD34 and HLA-DR. We considered this case as a 'presence of t (8; 21) in MPO (+), CD antigen (-) AML'. The myeloid lineage antigens are known to be expressed very early during myeloid differentiation whereas MPO (in its functional form) is viewed as being expressed relatively late in the process. Therefore, this case could be an example of 'asynchronous differentiation' in leukemia.

Keyword

Acute myeloid leukemia; Myeloperoxidase; CD13, CD14, CD15, CD33, t (8; 21)

MeSH Terms

Cytogenetics
Flow Cytometry
HLA-DR Antigens
Immunoglobulins
Leukemia
Leukemia, Myeloid, Acute*
Peroxidase
Phenotype*
HLA-DR Antigens
Immunoglobulins
Peroxidase