BURKITT'S LYMPHOMA

Alternate name: Burkitt's tumor, malignant lymphoma-Burkitt's type

endemic Burkitt's lymphoma in an African child

Overview: Burkitt's lymphoma is a solid tumor of B lymphocytes, caused by translocation and deregulation of the c-myc gene on chromosome 8. The characteristic feature of this entity is the dysregulation and mutation of the c-myc oncogene. It often results from a translocation between chromosomes 8 and 14. Three distinct forms of Burkitt lymphoma (BL) are identified: (1) endemic (African), (2) sporadic, and (3) immunodeficiency-associated subtypes. Although these forms differ in their clinical presentation and their epidemiology, they share the same aggressive clinical behavior and are histologically identical.

Phenotype/Characteristics:  The symptoms of Burkitt lymphoma depend on the type. The endemic (African) variant usually starts as tumors of the jaw or other facial bones, although it also can affect the gastrointestinal tract, ovaries, and breasts. It also can spread to the central nervous system, causing nerve damage, weakness, and paralysis. 

Sporadic and immunodeficiency-associated usually start in the bowel and form a bulky tumor mass in the abdomen, often with massive involvement of the liver, spleen, and bone marrow. These variants also can start in the ovaries, testes, or other organs, and spread to the brain and spinal fluid. 

Other symptoms associated with Burkitt lymphoma include:

•      Loss of appetite
•      Weight loss
•      Fatigue
•      Night sweats
•      Unexplained fever

Frequency: 98-99 % of cases are in Africa of the endemic variant. Outside of Africa, Burkitt lymphoma is rare. In the U.S., about 1,200 people are diagnosed each year, and about 59% of patients are over age 40. Burkitt lymphoma is especially likely to develop in people infected with HIV, with incidence estimated to be 1,000 times higher in HIV-positive people than in the general population.

Diagnosis: Prompt diagnosis is essential since Brukitt lymphoma spreads so quickly.

If suspected, all or part of an enlarged lymph node or other suspicious disease site will be biopsied. Additional tests may include:

•      Computed tomographic (CT) imaging of the chest, abdomen, and pelvis
•      Chest X-ray
•      PET or gallium scan
•      Bone marrow biopsy
•      Exam of spinal fluid
•      Blood tests to measure kidney and liver function
•      Testing for HIV disease.

Causes:

The exact cause and pathophysiologic mechanisms leading to the development of Burkitt lymphoma are not known. Malaria infection also probably plays a role in the pathogenesis of BL, as it can lead to inhibition of Epstein-Barr Virus-specific immune response, which has been strongly implicated in the endemic form. The virus has antigens and factors that inhibit the expression of anti-apoptotic proteins, leading to abnormal cell proliferation.

The classic reciprocal translocation (85% of cases) results in the transposition of the c-myc proto-oncogene on chromosome 8 with one of the immunoglobulin heavy chain genes on chromosome 14, which results in activation of the c-myc gene and is considered responsible for tumor proliferation. Overproduction of the c-myc product may change the lymphocytes into cancer cells, but other gene mutations may be responsible for the progression of Burkitt lymphoma (BL).

Treatment/Recommendations/Therapies:

Intensive intravenous chemotherapy is the preferred treatment for Burkitt lymphoma. Chemotherapy drugs are usually injected directly into the cerebrospinal fluid, a treatment known as intrathecal chemotherapy.

Examples of drugs that may be used in various combinations for Burkitt lymphoma include:

•      cyclophosphamide (Cytoxan)
•      cytarabine (Cytosar-U, Tarabine PFS)
•      doxorubicin (Adriamycin)
•      etoposide (Etopophos, Toposar, VePesid)
•      methotrexate (Rheumatrex)
•      vincristine (Oncovin) 

Other treatments for Burkitt lymphoma may include intensive chemotherapy in combination with:

•      Rituximab (Rituxan), a monoclonal antibody that sticks to proteins on cancer cells and stimulates the immune system to attack cancer cells.
•       Autologous stem cell transplantation, in which the patient's stem cells are removed, stored, and returned to the body.
•      Radiation therapy.
•      Steroid therapy. 

Information and support about the disease and the adverse effects of the drugs used to treat Burkitt lymphoma (BL) should be provided to patients and the family members, such as the following:

•      Secondary leukemias and myelodysplastic syndrome
•      Infertility
•      Possible anaphylactic reactions
•      Serious and potentially fatal infections

Young patients should be referred for counseling regarding fertility preservation, before chemotherapy, if possible.

Clearly explain transfusions (both red blood cells and platelets) and their associated complications.

Emotional support is very helpful to patients with cancer. Educating the medical personnel directly involved in patient care and the family members about emotional support for the patient is very important.

Support Groups:

Burkitt's Lymphoma Society

http://burkittslymphomasociety.com/

References:

Chang, R. (2010). Burkitt’s Lymphoma, WebMD. Retrieved March 12, 2013 from the URL: http://www.webmd.com/cancer/burkitt-lymphoma-prognosis-diagnosis-treatments

Kanbar, A. (2012). Burkitt Lymphoma and Burkitt-like Lymphoma, Medscape. Retrieved March 12, 2013 from the URL: http://emedicine.medscape.com/article/1447602-overview#aw2aab6b2b5aa

Photo from:
http://www.ografoundation.org/projects/burkitts/before.jpg