Burkitt lymphoma

Burkitt lymphoma is a highly aggressive B-cell non-Hodgkin's lymphoma characterized by rapid growth and a high proliferation rate. Three clinical variants share similar morphology, immunophenotype, and genetics, but they differ in etiology and epidemiology: endemic, sporadic, and HIV-related.

The pathophysiology of Burkitt lymphoma involves a chromosomal translocation of the MYC gene. In most cases, the t(8;14) translocation places MYC under the control of immunoglobulin heavy chain enhancer elements, leading to its constitutive expression. Additional genetic alterations, such as mutations in CCND3, TP53, and CDKN2A, contribute to oncogenesis. In endemic regions, chronic EBV infection combined with exposure to P. falciparum is thought to increase genomic instability through activation-induced cytidine deaminase. Similarly, in HIV-associated cases, persistent B-cell stimulation and viral microRNAs further facilitate the oncogenic process.

The incidence of Burkitt lymphoma in the US is reported at 5.95 per 1,000,000 in men and 2.36 per 1,000,000 in women. Endemic Burkitt lymphoma accounts for up to 50% of childhood cancers in endemic regions, with an annual incidence of 40-50 per million children. Sporadic cases show peak incidence at around 11 years in children and at about 30 years in adults, representing less than 1-2% of adult lymphomas.

Endemic variants are associated with EBV infection and primarily affect young boys in malaria-endemic regions. Sporadic forms are found in nonmalarial areas and may also be associated with EBV infection. The third variant is associated with HIV infection.

The sporadic variant commonly presents with abdominal involvement, characterized by abdominal pain, abdominal distension, gastrointestinal bleeding, nausea, and vomiting. It may also affect the head and neck region and, in rare cases, involve the CNS or mediastinum. The endemic variant most often presents with involvement of the jaw, facial, and periorbital regions. General systemic symptoms include fever, night sweats, weight loss, malaise, and lymphadenopathy.

Intensive combination chemotherapy can achieve cure rates of up to 90%.