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

Elisa Cannizzo,Antonio Azzarà,Mario Petrini,Sara Galimberti,Virginia Ottaviano,Giovanni Carulli,Luigi Del Vecchio,Frederic Preffer

doi:10.1155/2011/230568

Abstract

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.

Highlights

The distinction between Acute Undifferentiated Leukemia (AUL) and early Acute Lymphoblastic Leukemia (ALL) is complex and affects patient management options
We report a case of acute leukemia where a differential diagnosis between an early cyCD3-Tcell acute lymphoblastic leukemia (T-ALL) and an AUL was debated
The expression of CD34, HLA-DR, and CD7 has been shown in pro-T-ALL, in this case, blasts should express cyCD3 (Table 1) [2]

Summary

Introduction

The distinction between Acute Undifferentiated Leukemia (AUL) and early Acute Lymphoblastic Leukemia (ALL) is complex and affects patient management options. AUL is an acute leukemia with no more than one membrane marker of any given lineage. It lacks the T or myeloid lineage specific markers cyCD3 and MPO, respectively, and does not express B-lineage specific markers such as cyCD22, cyCD79a, or CD19. 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 [3, 4]. We report a case of acute leukemia where a differential diagnosis between an early cyCD3-T-ALL and an AUL was debated

Case Presentation

Discussion

38 PE-Cy7-A