Burkitt lymphoma (BL) is a monoclonal tumor of B cells occurring worldwide, which is hyperendemic in highly malarious areas of altitudes below 1 000 meters/3 000 feet with heavy rainfall (above 1 000 millimeters/40 inches a year), such as tropical Africa and lowland Papua New Guinea. African children commonly show jaw involvement. The tumor may also develop as a rare event in immunosuppressed patients (patients with organ transplant or familial X-linked immunodeficiency, and more commonly in AIDS). The tumors may be monoclonal, polyclonal or mixed; not all are Burkitt-type, but all are acute lymphoblastic sarcomas.

Epstein-Barr virus (EBV), a herpesvirus responsible for infectious mononucleosis, plays an important pathogenic role in about 97% of cases in Africa and Papua New Guinea, where EBV infection occurs in infancy and where malaria, an apparent cofactor, is holoendemic. EBV is also associated with Burkitt lymphoma in about 30% of cases in non-malarious areas and areas of low endemicity for Burkitt lymphoma (American form). Regardless of the presence of EBV, there is a specific chromosomal translocation t(8;14) involving the proto-oncogene c-myc locus on the long arm of chromosome 8 and the immunoglobulin heavy chain locus on chromosome 14. Variant translocations t(2;8) and (8;22) involve the c-myc gene and the immunoglobulin kappa and lambda chain loci, located, respectively on chromosomes 2 and 22. The subsequent activation of the c-myc gene plays an important role in malignant transformation. Recent studies suggest that the chromosomal breakpoint locations in African cases differ from those in American cases, suggesting a molecular heterogeneity in Burkitt lymphoma in general. Other genetic alterations include the inactivation of tumor suppressor gene p53. The estimated time range of tumor development is 2–12 years from primary EBV infection, but is much shorter in AIDS patients in whom an EBV-related lymphoma (often CNS) develops. Evidence from serology, virology and epidemiology points to a strong role of EBV infection in the causation of the African form of the disease.

Burkitt lymphoma is a highly aggressive tumor, but can nevertheless be cured in 90% of cases with intensive multiple chemotherapy. Prevention of EBV infection early in life and control of malaria (see Malaria, section 9) might reduce tumor incidence in Africa and Papua New Guinea. Subunit vaccines against EBV are in the trial stage. Chemotherapy is usually effective after the tumor develops. Cases should be reported to a tumor registry.