MOLECULAR ANALYSIS IN THE DIAGNOSIS OF PEDIATRIC LYMPHOMAS

Thirty-five pediatric lymphomas were categorized as either Burkitt's l ymphoma (BL), lymphoblastic lymphoma (LL), or large cell anaplastic ly mphoma (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) techniqu es were compared in the detection of immunogloblin heavy chain gene (I gH) rearrangement. T cell receptor beta (TCR beta) rearrangements were analyzed by SB and TCR gamma gene rearrangements by PCR. The PCR meth od of IgH and TCR gamma gene analysis was preferred to the SB methods, because there were fewer equivocal results in IgH gene analysis, TCR gamma rearrangement was more frequently detected than TCR beta in both lymphoblastic and large cell anaplastic lymphomas, and the PCR techni que 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 molec ular data were easily interpreted, occasional ambiguous results were s een due to genetic events other than antigen receptor gene rearrangeme nt affecting the genetic analysis. Thus, it is imperative to interpret these genetic data in the context of adequate morphological and immun ophenotypic analysis.