OBJECTIVETo investigate pathologic and differential diagnostic features of pediatric Burkitt lymphoma (BL).

METHODSA total of 20 cases of pediatric BL were retrospectively reviewed for their clinical and pathologic profiles. Bone marrow aspiration specimens were available in all cases and bone marrow biopsies were available for immunohistochemical study in 18 cases. Flow cytometry study was available in 16 cases. MYC translocation by FISH method was performed in 11 cases.

RESULTSAtypical lymphocytes with cytoplasmic vacuoles were found in bone marrow smears in all 20 cases and peripheral blood films in all 19 available cases. The bone marrow biopsies showed infiltration by uniform medium-sized atypical lymphocytes with multiple small nucleoli but without the starry-sky pattern in all 18 cases. Immunohistochemistry showed the following results in all 18 cases: positive for CD20, PAX-5, CD10, CD34 and TdT, but negative for bcl-2 and CD3 with Ki-67 > 95%.Flow cytometry showed CD19+CD20+CD10+FMC7+CD22+TdT-CD3- in 16 cases, including κ+ in 8 cases, λ+ in 7 cases, and κ-λ- in 1 case. MYC gene rearrangement by FISH was observed in 10 of the 11 cases.

CONCLUSIONSThe histopathology of BL is distinct, including atypical lymphocytes with cytoplasmic vacuoles in bone marrow aspirate, lack of starry-sky patternin bone marrow biopsy. Generally, the diagnosis should be made with a combined immunophenotype and FISH approach. Pediatric BL must be distinguished from DLBCL and B-cell lymphoma, unclassifiable, which has intermediate features between DLBCL and Burkitt lymphoma.

Biopsy ; Bone Marrow ; pathology ; Burkitt Lymphoma ; genetics ; pathology ; Child ; Diagnosis, Differential ; Female ; Flow Cytometry ; Genes, myc ; Humans ; Immunohistochemistry ; Immunophenotyping ; In Situ Hybridization, Fluorescence ; Lymphocytes ; pathology ; Lymphoma, B-Cell ; pathology ; Lymphoma, Large B-Cell, Diffuse ; pathology ; Male ; Retrospective Studies ; Translocation, Genetic

No abstract available.
Bone Marrow/pathology ; Burkitt Lymphoma/*diagnosis/genetics ; Child ; Chromosomes, Human, Pair 1 ; Female ; Flow Cytometry ; Humans ; Immunoglobulin Heavy Chains/genetics ; Isochromosomes/*genetics ; Karyotype ; Karyotyping ; Proto-Oncogene Proteins c-myc/genetics ; Republic of Korea ; Translocation, Genetic

Acquired Immunodeficiency Syndrome ; drug therapy ; genetics ; surgery ; Adult ; Burkitt Lymphoma ; drug therapy ; genetics ; surgery ; virology ; Diagnosis, Differential ; Female ; Genes, myc ; HIV ; isolation & purification ; HIV Infections ; Herpesvirus 4, Human ; genetics ; Humans ; Immunohistochemistry ; Lymphoma, AIDS-Related ; drug therapy ; genetics ; surgery ; virology ; Lymphoma, B-Cell ; pathology ; Lymphoma, Mantle-Cell ; pathology ; Male ; Middle Aged ; RNA, Viral ; analysis ; Sarcoma, Myeloid ; pathology ; Translocation, Genetic

OBJECTIVETo investigate the molecular genetic features and diagnostic aspects of sporadic Burkitt's lymphoma (BL) in children.

METHODSTissue microarray was constructed to include 64 cases of pediatric BL and 6 cases of pediatric diffuse large B-cell lymphoma (DLBCL). Immunohistochemistry and fluorescence in-situ hybridization for c-myc, bcl-2, bcl-6, IgH, myc/IgH and bcl-2/IgH gene were performed. Cases of pediatric Burkitt's lymphomas were subclassified into three groups based on their cellular orgins: the germinal center (GC) group, the late-germinal center (late-GC) group and the post-germinal center (post-GC) group.

RESULTSAmong 64 Burkitt's lymphomas studied, expression of CD20, CD10, bcl-6, bcl-2 and MUM1 by immunohistochemistry were 100% (64 cases), 98.4% (63 cases), 96.9% (62 cases), 0 (0 cases) and 23.4% (15 cases), respectively. Various gene rearrangements were found involving the c-myc 93.1% (54/58 cases) and IgH 82.8% (48/58 cases). Detailed rearrangements are as follows: 46 cases (85.2%) myc/IgH gene translocation along with c-myc and IgH gene rearrangement; 4 cases (7.4%) c-myc gene rearrangement without IgH and myc/IgH abnormality; 4 cases (7.4%) without c-myc, IgH or myc/IgH gene rearrangement. No case showed bcl-2 gene abnormality (100%). Fifty nine cases showed normal bcl-6 gene status. One case had bcl-6 gene rearrangement and amplification with the pathologic and immunophenotypic characteristics of BL, leading to a revised pathological diagnosis of B-cell lymphoma, unclassifiable with features intermediate between diffuse large B-cell lymphoma and Burkitt's lymphoma (DLBCL/BL). Two cases showed c-myc gene rearrangement. Two cases showed bcl-6 gene amplification and 6 DLBCL cases had a normal status of bcl-2/IgH.

CONCLUSIONSA majority of pediatric sporadic BL arise from the germinal center B cells, most of which have c-myc gene rearrangement. It is useful to distinguish BL and DLBCL by multiple genes detection.

Antigens, CD20 ; metabolism ; Burkitt Lymphoma ; genetics ; metabolism ; pathology ; Child ; Child, Preschool ; Diagnosis, Differential ; Female ; Gene Rearrangement, B-Lymphocyte, Heavy Chain ; Genes, myc ; genetics ; Humans ; Immunoglobulin Heavy Chains ; genetics ; Lymphoma, Large B-Cell, Diffuse ; genetics ; metabolism ; pathology ; Male ; Neprilysin ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Proto-Oncogene Proteins c-bcl-6 ; metabolism ; Translocation, Genetic

No abstract available.
Adolescent ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use ; Burkitt Lymphoma/*pathology ; Child, Preschool ; Cyclophosphamide/therapeutic use ; Doxorubicin/therapeutic use ; Female ; Gene Rearrangement ; Herpesvirus 4, Human/metabolism ; Humans ; Immunohistochemistry ; Lymphoma, B-Cell/*diagnosis/drug therapy ; Lymphoma, Large B-Cell, Diffuse/*pathology ; Male ; Prednisone/therapeutic use ; Proto-Oncogene Proteins c-myc/genetics ; Tomography, X-Ray Computed ; Vincristine/therapeutic use ; Viral Matrix Proteins/immunology/metabolism