burkitt lymphoma | Burkitt lymphoma

Burkitt lymphoma

Burkitt lymphoma or Burkitt cell leukemia is a rare form of cancer of the lymphatic system — mainly associated with B-lymphocytes — which predominantly affects young people, most commonly described in Central Africa, although it has also been in other Areas of the world. The form seen in Africa appears to be associated with Epstein Barr virus infection, although the pathogenetic mechanism is unknown. 1 The eponymous comes from the surgeon Denis Parsons Burkitt who, working in Equatorial Africa, described the disease in 1956.2

Burkitt's lymphoma results from a characteristic chromosomal translocation that affects the MYC gene. A chromosomal translocation means that the chromosome has ruptured, allowing its binding with other chromosomal parts. In Burkitt lymphoma it affects chromosome 8 (MYC gene locus), which changes the expression pattern of the MYC gene altering its natural function of control in cell growth and proliferation. The most frequent variant produces a translocation of chromosome 8 to 14 — t (8; 14) (Q24; q32) — 1 while other variants include translocations to other chromosomes — t (2; 8) (P12; q24) and T (8; 22) (q24; q11). A much less frequent translocation has also been identified between three chromosomes, T (8; 14; 18). 3 Index
1 classification
2 Histology
3 Malignant B-cells
4 See Also
5 References
Classification

Burkitt lymphoma is classified into three clinical variants, endemic, sporadic and immunodeficiency-associated: 1 The endemic variant occurs in Equatorial Africa, is the most frequent malignancy among children in that region of the world. Children affected by the disease usually also have a chronic malaria infection that is believed to be the reason why resistance to Epstein-Barr virus has been reduced. The disease tends to affect the jaw and other facial bones, distal ileum, cecum, ovaries, kidney, and female breast.
The sporadic variant of Burkitt or non-African lymphoma is located outside of Africa. Tumor cells have a similar appearance to classic or endemic Burkitt lymphoma, and it is also believed that deficient immunity provides an entry point for an infection with the Epstein-Barr virus. Non-Hodgkin lymphomas, which include Burkitt's lymphoma, constitute between 30-50% of childhood lymphomas. Compared to the endemic variant, the jaw is not affected, but it is more common to see the region Ileo-cecal more involved.
associated with immunodeficiency, especially HIV or a transplant or a patient receiving immunosuppressive drugs are affected. In fact, Burkitt's lymphoma tends to be the first manifestation of AIDS and is common in Western countries.
Morphologically it is virtually impossible to distinguish these three clinical variants. Burkitt lymphoma associated with immunodeficiency can be seen with a more plasmatic-like appearance or with more pleomorphism, although these are not specific characteristics.

Histology
Burkitt lymphoma under the microscope consists of a monotonous population of medium-sized cell layers with a great proliferative and apoptotic activity. The appearance resembles a night of stars, by reason of the scattered inclusions of macrophages that have digested the dead cell parts. The tumor cells have a very similar size to the histiocytes or endothelial cells, so they are not very large cells, but medium size. Tumor cells have a small amount of cytoplasm that is stained basophilic. Cell contours have the appearance of being quadrilateral.

Burkitt's lymphoma under the microscope.
Malignant B-cells
Normal B cells possess genes for the heavy chain and the immunoglobulins light chain. Each B cell has its unique configuration of heavy and light chains that are unique in each individual cell. However, as Burkitt cells come from proliferating processes, each tumor cell of a patient tends to possess identical heavy chain genes. Therefore, when analyzing a blood electrophoresis of a patient with Burkitt lymphoma, a clonal band is formed by genes of the Ig heavy chain that have migrated to the same position. Other infectious diseases such as infectious mononucleosis lack this electrophoretic clonal band.