Molecular Analysis in the Diagnosis of Pediatric Lymphomas

Abstract

Thirty-five pediatric lymphomas were categorized as either Burkitt ‘s lymphoma (BL), lymphoblastic lymphoma (LL), or large cell anaplastic lymphoma (LCAL) by histological and immunophenotypic methods. They were further characterized by molecular analysis of their antigen receptor genes. Southern blot (SB) and polymerase chain reaction (PCR) techniques were compared in the detection of immunogloblin heavy chain gene (IgH) rearrangement. T cell receptor β (TCRβ) rearrangements were analyzed by SB and TCRγ gene rearrangements by PCR. The PCR method of IgH and TCRγ gene analysis was preferred to the SB methods, because there were fewer equivocal results in IgH gene analysis, TCRγ rearrangement was more frequently detected than TCRβ in both lymphoblastic and large cell anaplastic lymphomas, and the PCR technique was more rapid, required less DNA, and could be used with archival material. In addition, analysis of IgH gene rearrangement by PCR was more specific for assessing B cell lineage. Although most of the molecular data were easily interpreted, occasional ambiguous results were seen due to genetic events other than antigen receptor gene rearrangement affecting the genetic, analysis. Thus, it is imperative to interpret these genetic data in the context of adequate morphological and immunophenotypic analysis.

Key Words:

• immunoglobulin gene
• malignant lymphoma
• polymerase chain reaction
• T cell receptor gene