Prethymic Cytoplasmic CD3 Negative Acute Lymphoblastic Leukemia or Acute Undifferentiated Leukemia : A Case Report

Abstract EN

Acute undiffentiated leukemia (AUL) is an acute leukemia with no more than one membrane marker of any given lineage.

Blasts often express HLA-DR, CD34, and/or CD38 and may be positive for terminal deoxynucleotidyl transferase (TdT).

The expression of CD34, HLA-DR, and CD38 has been shown in pro-T-ALL, although in this case, blasts should also express CD7 and cyCD3.

However, some cases of T-ALL without CD3 in the cytoplasm and all TCR chain genes in germ line configuration are reported, features that fit well with a very early hematopoietic cell.

We report a case of acute leukemia CD34+/−HLADR+CD7+CD38+cyCD3− in which a diagnosis of AUL was considered.

However the blasts were also positive for CD99 and TCR delta gene rearrangement which was found on molecular studies.

Therefore a differential diagnosis between AUL and an early cyCD3 negative T-ALL was debated.