Table 2. Major Histopathological Categories of Non-Hodgkin Lymphoma in Children and Adolescentsa
CNS = central nervous system; ML = malignant lymphoma; REAL = Revised European-American Lymphoma; WHO = World Health Organization.
a Adapted from Percy et al.
|Category (WHO Classification/ Updated REAL)||Category (Working Formulation)||Immuno-phenotype || Clinical Presentation ||Chromosome Translocation ||Genes Affected|
|Burkitt and Burkitt-like lymphomas||ML small noncleaved cell||Mature B cell||Intra-abdominal (sporadic), head and neck (non-jaw, sporadic), jaw (endemic) ||t(8;14)(q24;q32), t(2;8)(p11;q24), t(8;22)(q24;q11)||C-MYC, IGH, IGK, IGL|
|Diffuse large B-cell lymphoma || ML large cell ||Mature B cell; maybe CD30+ ||Nodal, abdominal, bone, primary CNS (when associated with immunodeficiency), mediastinal||No consistent cytogenetic abnormality identified ||�|
|Lymphoblastic lymphoma, precursor T-cell leukemia, or precursor B-cell lymphoma ||Lymphoblastic convoluted and non-convoluted ||Pre-T cell ||Mediastinal, bone marrow ||MTS1/p16ink4a Deletion TAL1 t(1;14)(p34;q11), t(11;14)(p13;q11) ||TAL1, TCRAO, RHOMB1, HOX11 |
|Pre-B cell ||Skin, bone |
|Anaplastic large cell lymphoma, systemic || ML immunoblastic or ML large||CD30+ (Ki-1+) ||Variable, but systemic symptoms often prominent|| t(2;5)(p23;q35) ||ALK, NPM|
|T cell or null cell|
|Anaplastic large cell lymphoma, cutaneous ||�|| CD30+ (Ki-usually) ||Skin only; single or multiple lesions||Lacks t(2;5)||�|
Burkitt and Burkitt-like lymphoma/leukemia
Burkitt and Burkitt-like lymphoma/leukemia in the United States accounts for about 30% of childhood NHL and exhibits consistent, aggressive clinical behavior.[2,3,7] The overall incidence of Burkitt lymphoma is 2.5 cases per million person-years and is higher among boys than girls (3.9 vs. 1.1).[2,8] The two most common primary sites of disease are lymph nodes, especially of the head and neck region, and the abdomen.[3,8] Other sites of involvement include testes, bone, skin, bone marrow, and central nervous system (CNS). Although 85% or more of Burkitt lymphoma is associated with the Epstein Barr virus (EBV) in endemic Africa, approximately 15% of cases in Europe or the United States will have EBV detectable in the tumor tissue.
The malignant cells show a mature B-cell phenotype and are negative for the enzyme terminal deoxynucleotidyl transferase (TdT). These malignant cells usually express surface immunoglobulin, most bearing surface immunoglobulin M with either kappa or lambda light chains. A variety of additional B-cell markers (e.g., CD20, CD22) are usually present, and almost all childhood Burkitt/Burkitt-like lymphoma/leukemia express CALLA (CD10). Burkitt lymphoma/leukemia expresses a characteristic chromosomal translocation, usually t(8;14) and more rarely t(8;22) or t(2;8). Each of these translocations juxtaposes the c-myc gene to immunoglobulin locus regulatory elements, resulting in the inappropriate expression of c-myc, the gene involved in cellular proliferation. Pediatric Burkitt lymphoma patients whose tumors contain cytogenetic abnormalities involving gain of 7q or deletion of 13q appear to have an inferior outcome on current chemotherapy protocols.[10,11]