title: Burkitt lymphoma/leukaemia transformed from a precursor B cell: clinical and molecular aspects.
abstract: Burkitt lymphoma/leukaemia (BL/L) is a heterogeneous disease with respect to epidemiological patterns and cell origin. The occurrence of BL/L with an immature phenotype raises the question whether this phenotype might be a consequence of early B-cell transformation or, alternatively, a secondary feature of transformed, mature B cells. It also poses important clinical questions regarding diagnosis and therapeutic procedures. Here we describe the case of a 4-yr-old child with BL/L and FAB L3 morphology, with phenotypic and genotypic characteristics of a CD10+ precursor B-cell acute lymphoid leukaemia (ALL) associated with t(8;14)(q24;q32). Molecular analysis showed expression of RAG1 and RAG2 and an unmutated VDJCmu immunoglobulin rearrangement coinciding with a lack of AICDA expression, indicating an immature B-cell origin. His clinical response suggested that FAB L3 ALL with MYC rearrangement and an aberrant precursor B-cell phenotype is clinically similar to BL/L. Moreover, short, intensive chemotherapeutic protocols seemed to be beneficial. This case also allowed us to refine the description of cellular and molecular variants of BL/L regarding the cell origin and pathogenesis of this biologically heterogeneous disease.
authors.affiliation: Bone Marrow Transplantation Centre (CEMO), Instituto Nacional de Câncer, Rio de Janeiro, Brazil. biomol@inca.gov.br
authors.forename: Rocio
authors.initials: R
authors.lastname: Hassan
authors.forename: Fabricio
authors.initials: F
authors.lastname: Felisbino
authors.forename: Claudio Gustavo
authors.initials: CG
authors.lastname: Stefanoff
authors.forename: Virginia
authors.initials: V
authors.lastname: Pires
authors.forename: Claudete E
authors.initials: CE
authors.lastname: Klumb
authors.forename: Jane
authors.initials: J
authors.lastname: Dobbin
authors.forename: Héctor N
authors.initials: HN
authors.lastname: Seuánez
authors.forename: Ilana Zalcberg
authors.initials: IZ
authors.lastname: Renault
mesh_terms: D002051:Burkitt Lymphoma / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D002454:Cell Differentiation / Q000502:physiology; D002471:Cell Transformation, Neoplastic / Q000378:metabolism / Q000473:pathology*; D002675:Child, Preschool; D003937:Diagnosis, Differential; D050939:Gene Fusion; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain; D016259:Genes, myc; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology*; D054448:Precursor Cells, B-Lymphoid / Q000378:metabolism / Q000473:pathology*
chemical_list: D007143:Immunoglobulin Heavy Chains