Burkitt's Lymphoma/Leukemia

Dr. Mark Minden

Princess Margaret Hospital

BURKITT'S LYMPHOMA/LEUKEMIA

Burkitt's lymphoma/leukemia is a malignancy of B-cells. The disease exists in two forms, an African form or a non-African form. The African form occurs in equatorial Africa and is associated with infection by the Epstein Barr virus. This disease develops in children and frequently involves lumps in the jaw.

The non-African form of Burkitt's Lymphoma can present as a lymphoma or a leukemia, the distinction being whether or not there is involvement of bone marrow. In this form of the disease, lymph nodes in the abdomen, chest or neck are frequently involved. In addition spread to the bone marrow is common. Like other B-cell leukemias, the disease can also spread to the membranes lining the brain. Among the leukemias and lymphomas, Burkitt Lymphoma cells are marked by their rapid growth rate.

The diagnosis of Burkitt's Lymphoma is made by biopsy of an involved lymph node or the finding of cells in the bone marrow. Burkitt Lymphoma cells are small non-cleaved cells, with a dark blue cytoplasm and prominent cytoplasmic vacuoles that has resulted in the 'starry sky' description of the cells. The nuclei are generally large, with prominent nucleoli. Study of the chromosomes of Burkitt Lymphoma cells has shown the presence of an abnormal myc gene in almost all of the cases. This change results in high level expression of the myc protein which drives cells into proliferation. In addition to the change in the myc gene are frequent abnormalities of the p53 gene. P53 is important in protecting the cell against a variety of stresses. The mutations that occur in p53 in Burkitt Lymphoma cells, block the ability of p523 to carry out its normal functions.