Background and objective: Sporadic Burkitt's lymphoma (sBL) is uncommon and its relation to Epstein-Barr virus (EBV) is unknown in China. This study was to investigate the clinical presentation, morphologic features, immunophenotype and EBV infection status of sBL in Guangzhou district, a prevalent area of EBV infection.
Methods: The clinical data of 21 sBL patients were reviewed. A panel of immunohistochemical staining was performed and EBV-encoded small RNAs (EBERs) in situ hybridization was applied to identify EBV infection.
Results: From January 2000 to October 2007, 21 cases(0.87%) of sBL were confirmed among 2416 cases of non-Hodgkin's lymphoma(NHL) in Sun Yat-sen University Cancer Center. Male to female ratio was 4.25 (17/4). The median age was 23 years. Of the 21 patients, 19 (90.48%) had lymph node(s) involvement; 16 (76.19%) had multiple sites involvement; 12 (57.14%) were at advanced stages (III/IV). The 2-year survival rate of 15 patients who received chemotherapy or resection plus chemotherapy was 56.00%. Twenty cases showed the prototypic morphology of sBL, and one was the variant of sBL with plasmacytoid differentiation. The main immunophenotype of these 21 sBLs was sIgM+/CD20+/CD10+/Bcl-6+/Bcl-2-[or Bcl-6+(>95%)/Bcl-2+(<10%)]/TdT-/Ki-67+ 100%. Of 20 detectable cases, 11 showed CD5 expression in a few (3%-20%) tumor cells. P53 was overexpressed in ten cases (47.62%). Six cases (28.57%) had EBV infection, with EBNA1 and EBERs expression, but not LMP1. There were no significant differences in morphology and immunophenotype between EBV-positive and EBV-negative cases.
Conclusions: sBL is uncommon in Guangzhou district, mainly seen in boys and young men. Most patients had lymph node(s) involvement, showing similar morphology and immunophenotype as that of endemic BL. Type I EBV latent infection is associated with 28.57% of cases.