BURKITT'S LYMPHOMA

I borrowed this from Vanderbilt University's website

Also checkout this site Burkitts.Org

BURKITT'S LYMPHOMA

Burkitt's lymphoma is a B cell neoplasm characterized by small noncleaved cells that are uniform in appearance and that produce a diffuse pattern of tissue involvement. This neoplasm is one of the fastest growing malignancies in humans. The cells of Burkitt's lymphoma are characterized by a specific cytogenetic defect, a balanced, reciprocal translocation of genetic material from the long arm of chromosome 8 to the long arm of chromosome 14.

Two variants of Burkitt's lymphoma are recognized: African and non- African; although very similar in histologic and cytologic features, they have very different epidemiologic patterns and clinical presentations. African Burkitt's lymphoma presents most often as a jaw or orbital tumor and occurs endemically in central Africa. It is interesting to note that this same central African region is also the endemic area for malaria and yellow fever. In contrast non- African Burkitt's lymphoma occurs outside this endemic region and presents primarily as an abdominal mass.

In the African type, the Epstein- Barr virus has been strongly implicated, while for the non- african type the relationship is less clear. Burkitt's lymphoma is a monoclonal proliferation of B lymphocytes. The lymphocytes have receptors for the EBV and are its specific target. African children who develop Burkitt's lymphoma are thought to be unable to mount an appropriate immune response to primary EBV infection, possibly because of co- existent malaria which is immunosuppressive. Months to years then pass during which excessive B cell proliferation occurs.

African Burkitt's most often presents with rapidly growing jaw or orbital masses. Abdominal tumors are slightly less common and may arise from kidneys, ovaries, or retroperitoneal structures. Infrequent sites of involvement are bone, testes, breasts, thyroid, parotid, and skin. Conspicuously absent are nodal and bone marrow involvement.

Non- African Burkitt's presents as a facial mass and much more commonly as an abdominal mass that is sometimes associated with pain or obstructive symptoms. In this context, it is more likely to arise in the Peyer's patches of the ileocecal region or in mesenteric nodes. Ileocecal tumors may serve as the lead point for an intussusception and indeed lymphoma is the most frequent cause of an intussusception in children older than 6 years. Other distinct sites of initial involvement are the cervical lymph nodes and the bone marrow.

Burkitt's lymphoma is more common in males and tends to occur in pediatric patients beyond the peak age range for common childhood leukemia. The mean age in Africa is 7 years while those cases outside Africa have a mean of 11 years. The staging of Burkitt's lymphoma is summarized in the accompanying Table.

The single most important agent for the treatment of Burkitt`s lymphoma is the alkylating agent cyclophosphamide. Current modes of therapy for Burkitt's lymphoma include the combination of cyclophosphamide, vincristine, methotrexate, and prednisone (Comp). Most patients also receive CNS prophylaxis with intrathecal methotrexate and craniospinal radiation. The current 3 year relapse free survival rate for patients with local disease is approximately 80%. Because of the rapid rate of growth and large tumor burden present in most children with Burkitt's lymphoma, here is a risk of tumor lysis syndrome.