Burkitt Lymphoma: A Study Of Clinicopathology, Immunophenotype And T(8;14) Translocation

Background and Objectives Burkitt Lymphoma (BL) is a highly aggressive lymphoid neoplasm arising from germinal center B-cells. It is frequently seen in the equator Africa but also seen all over the world. A retrospective study of clinicopathology was made for 87 cases of sporradic BL, with immunophnotype analysis, detection of Epstein Barr virus infection and t(8;14) translocation. The purpose is to investigate the clinical and pathologic features of the tumor and to evaluate the significances and effects of immunophenotype and t(8;14) in diagnosis and differential diagnosis of the tumor. Statistic analysis was used for evaluation of prognosis related factors of the tumor.Materials and Methods 87 cases of BL were selected from the files of Pathology Department, West China Hospital of Sichuan University in period of Jan 1990 to Jan 2007. Related clinical data were collected and follow up was performed for all of the cases. Statistics was used for survival analysis of the tumors. Pathologic diagnosis was according to the WHO classification for tumors of hematopoietic and lymphoid tissue (2001). Immunophenotype analysis was performed by SP method. Antibodies selected were included CD20, CD3/CD45RO, CD10, BI-6, Mum-1, TDT, c-Myc and Ki-67. ISH and FISH were used for detection of EBER and t(8;14)respectively. Results (1) Clinical manifestations: There were 38 cases ofchildhood BL, the age ranged from 2～13 Y (mean 8Y), the ratio ofmale and female was 8.5:1. there are 49 cases of adult BL, the ageranged from 15～69Y (mean 33Y), the ratio of male and female was1.6:1. The course of disease was 1 to 10 months. The celiac organs(36.8%) were the most commonly involved followed by superficiallymph nodes (26.7%) and the head and neck.(26.4%). 60% of patientswere in stage I and II at presentation, and 54% of them had Bsymptoms. Thrombocytopenia and increased serum level of LDH werefound in 50% of cases as well. (2) Pathology: Basing on WHOclassification for tumors of hematopoietic and lymphoid tissue (2001),46 of 87 cases (52.9%) belong to classical BL which included 32 ofchildhood and 14 of adult cases, and the remaining 41(47.1%) wereatypical BL which included 6 of .childhood and 35 of adult cases. (3)Immunophenotype: the tumor cells of all cases expressd B-celldifferentiation antigen and also share the germinal center B phenotype(CD10+ or CD10-/Bcl-6+/mum1-) but CD3 and TdT. CD45RO waspositive in 9.4%(6/64) of cases. The tumor cells of all cases werenegative for Bcl-2 but one. Ki-67 index was in 80%～100%. (4)Detection of EBER and t(8;14): EBER was positive in 8 of 64 cases(12.5%).t(8;14) was confirmed by FISH in 27/34 cases (79.4%) andthere was no difference in childhood and adult cases. (5) Therapy andprognosis: the therapy and follow up data was available in 66 cases(75.9%), 28 patients (42.4%) had accepted the operation for cutting offthe tumor and 15 of them had received chemotherapy following theoperation; chemotherapy was used alone in 18 patients(27.3%) andthe remaining 20 cases got no treatment after the diagnosis wasestablished. CHOP was used in 16 of 27 patients (59.2%). The rate of CR and PR were 27.3% and 54.5% respectively. In all 66 cases, 43 patients (65%) were died of the disease and the remaining 23 patients (35%) are still alive, the average survival time is 23.2 months (median 8 months). The overall survival (OS) rates of 1, 2 and 5 year were 35.2%, 32.9% and 32.9% respectively. Both staging and serum leave of LDH were prognosis related factors which showed significantly difference statistically.Conclusions Burkitt lymphoma shows some features in clinical manifestations and pathology. The diagnosis of BL could be established basing on morphology and immunophenotype analysis in most of conditions. Detection of t(8;14) translocation is helpful in diagnosis of the tumor. The poor prognosis in this group of cases may be related to giving up or unsuitable treatment of chemotherapy.