The immunophenotype of pre-TALL/LBL revisited

Robert E Lewis1, Julius M Cruse, Catherine M Sanders

  • 1Department of Pathology, University of Mississippi Medical Center, 2500 North State Street, Jackson, Mississippi 39216, USA.

Insights

Flow cytometry for cluster of differentiation (CD) markers aids in diagnosing T cell acute lymphoblastic leukemia (T-ALL)/lymphoblastic lymphoma (LBL). This study suggests reevaluating the World Health Organization

Area of Science:

  • Hematology
  • Immunology
  • Oncology

Background:

  • Flow cytometric analysis of cluster of differentiation (CD) markers is essential for diagnosing precursor T cell acute lymphoblastic leukemia (T-ALL)/lymphoblastic lymphoma (LBL).
  • The World Health Organization (WHO) provides guidelines for the immunophenotype of pre-T ALL/LBL, including typical marker expressions and variations.

Purpose of the Study:

  • To analyze the expression of selected CD markers in 19 cases of pre-T ALL/LBL.
  • To evaluate the current WHO-defined immunophenotype for pre-T ALL/LBL based on observed marker expression patterns.

Main Methods:

  • Flow cytometric analysis was performed on 19 cases of pre-T ALL/LBL.
  • Expression levels of various CD markers including TdT, cCD3, CD7, CD2, CD3, CD4, CD5, CD8, CD10, CD13, CD33, CD117, and cCD79a were assessed.

Main Results:

  • High positivity rates were observed for TdT (73.3%), cCD3 (100%), CD7 (100%), and CD5 (100%).
  • Variable expression was noted for CD2 (77.8%), CD3 (38.9%), CD4 (61.1%), CD8 (50%), and CD10 (47.1%).
  • Myeloid antigen expression (CD13, CD33, CD117) and dual CD4/CD8 expression were infrequent, contrary to typical expectations.

Conclusions:

  • The study findings indicate discrepancies between observed CD marker expression and the current WHO-defined immunophenotype for pre-T ALL/LBL.
  • Further extensive research is needed to reevaluate and potentially revise the diagnostic immunophenotype criteria for pre-T ALL/LBL.

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