burkitt lymphoma prognosis | Burkitt's lymphoma

Burkitt's lymphoma

Burkitt's lymphoma is a tumor (non-Hodgkin's lymphoma) that comes from malignant evolution and proliferation of B-type lymphoid cells. It is often of viral origin. Classically, three clinical variants are defined [1]: The endemic form, the form associated with immunodeficiency and the sporadic form

Causes Change
The Epstein-Barr virus is associated with the three forms of Burkitt lymphoma, consistently in the endemic form, inconsistently in the other two forms [3]. Infection precedes tumor development [4]. The mechanism of tumor transformation is not clear. Several proteins synthesized by the Epstein-Barr virus genome would be implicated, resulting in alterations in the DNA of the contaminated cell [5].

The supporting role of malaria was suspected in the endemic form for epidemiological reasons. Some parasite antigens may reactivate the Epstein-Barr virus present in a host [6].

Genetic characteristics

Burkitt's lymphoma is generally associated with a translocation of the C-MYC gene (the MYC gene was discovered for the first time in patients with Burkitt lymphoma). This translocation is often caused by the viral oncogene EBV.

Most common sites in the Genome: t (8; 14) (q24; q32) chromosome 8, Q24 region to chromosome 14, Q32 region [7]
Variants: From chromosome 8 to chromosomes 2 or 22 t (8; 2) (q24; p12); T (8; 22) (Q24; q11)
EBV Genome Integration: 100% in Africa, 30% elsewhere [8]
Anatomo-Pathology

It is the fastest growing tumor with a doubling of cellular time between 1 and 2 days [3].

Histologically, this cancer is described as having an appearance of "Starry Sky" [9]. Lymphoid cells, particularly similar to each other, are organized into layers of cells with very high rates of proliferation and apoptosis.

Characteristic appearance of cells in case of Burkitt lymphoma.
These lymphocytes have a round or oval-shaped nucleus, with regular contours, chromatin, located in the central part of the nucleus, found to be reticulate with several nucleoli of ordinary size. The cytoplasm is basophile to the examination. In immunocompromised patients, it is also possible to discover a significant differentiation of the cytoplasm with a single nucleolus nucleus.

Symptoms

It will often be possible to discover either a large osteolytic lesion of the maxilla or mandible or a rapidly growing abdominal mass.

There are no clear clinical delimitations between the three forms, the distinction being rather at the epidemiological level.

Clinical Forms Modify

Endemic form linked to Epstein-Barr virus (EBV)

This pathology takes its name from Denis Parsons Burkitt (1911-1993), the military surgeon who described it in 1958 in Uganda [10]. He had noticed jaw tumors never described yet common among children in the area. Nevertheless, it will only be six years later in Zaire (now DRC) that the first clinical descriptions of this lymphoma will be carried out. Initially taken for a sarcoma, it is properly classified in lymphomas from 1960 [11]. The viral cause was suspected in 1964 by Epstein, Barr, and Hong Kong in the presence of viral corpuscles in the lymphoma samples [12].

This is the first discovery tumor associated with a virus and one of the first associated with chromosomal translocation [3].

Epidemiology Modify

It is mainly found in African children with a peak of frequency between 6 and 7 years. The most common childhood tumor in Equatorial Africa, in the famous Lymphoma Belt [13], is linked to the enormous prevalence of EBV in this region. The prevalence zone of the disease covers malaria [14]. The disease affects boys more often than girls and regularly attacks the jaw. It can also affect other bones of the face or abdomen but the proportions of these different forms vary according to sources [15], [16] (retroperitoneal region, ovaries or mesentery).

Burkitt's lymphoma currently represents in the world 2% of all lymphoproliferative syndromes [17] (i.e. the whole containing lymphomas, leukemias, myeloma, etc.).

HIV-related form

The AIDS epidemic has made HIV a cause of Burkitt's lymphoma to be systematically investigated when associated with immunodeficiency [18], although immunosuppressive agents used in a transplant may also be implicated. The form of HIV-related lymphoma appears clinically difficult to distinguish from the classical form.

Sporadic or "Non-African" form change

A rare disease that can be found anywhere in the world, it affects adults as well as children especially in the abdomen. It does not appear to be associated with Epstein-Barr virus [3].

Prognostic factors Modify

The extension (local, loco-regional or generalized) is an important prognostic factor. Some chromosomal anomalies have a more pejorative evolution [19].

Change processing

After the puncture of the tumor mass and the extension balance (radiography, myelogram, lumbar puncture), progressive and exclusive chemotherapy should be considered. This one cures 80% of the cases. In case of relapse or non-efficacy, treatment should be broadened (immunotherapy, radiotherapy) but the prognosis is darkened (only 10 to 20% cure).

As with all cancers, early management is paramount in reducing mortality.

The management of this lymphoma in poor countries is much more limited.

Prevention change

The fight against Epstein-Barr virus (EBV) and HIV is, of course, the basis of prevention. There is no vaccine available for EBV yet, but clinical trials are underway [20] [21]. The prevention of these two pathologies is therefore considered to be the key to the prevention of Burkitt lymphoma.