Monday 16 August 2004
Burkitt lymphoma takes three .
Endemic Burkitt lymphoma most commonly affects children and exhibits a male predominance. It is common in equato-rial Africa and New Guinea and is strongly associated with EBV infection.
Sporadic Burkitt lymphoma is less com-monly related to EBV infection and affects both children and adults, with a bimodal age distribution.
Immunodeﬁciency-related Burkitt lymphoma is seen in the setting of congenital immunodeficiency, HIV infection, and posttransplant.
Burkitt lymphoma is one of the most rapidly replicating of all human tumors, and patients frequently present with the sudden development of large tumor masses.
In endemic Burkitt lymphoma, the tumor shows an unexplained predilection for areas of growth, including the sockets around deciduous teeth of young (2- to 4-year-old) children, and hormonally responsive locations, such as the breasts of pubertal and pregnant women, ovaries, testes, and thyroid.
In sporadic and immunodeﬁciency-associated Burkitt lymphoma, visceral involvement, particularly of the small bowel, is common, with initial symptoms related to obstruction or perforation.
Burkitt lymphoma diffusely effaces the nodal architecture.
A monomorphic proliferation of intermediate-sized cells is seen (nuclear size similar to that of histiocytes or endothelial cells); the round or oval nuclei have a thick nuclear membrane and two to four nucleoli, and the cytoplasm is moderately amphophilic.
Many Burkitt lymphomas have a somewhat cohesive appearance, and the cell borders maintain a molded contour, particularly at the periphery.
The mitotic rate is high (MIB-1/KI-67 is positive in >95% of cells), and necrosis is often present, particularly at the periphery.
Evenly distributed macrophages containing cellular debris give a mottled (“starry sky”) appearance to Burkitt lymphoma at low power.
Some classiﬁcation systems make a distinction between “Burkitt” and “non-Burkitt” mor-phology of small noncleaved cell lymphomas; however, the criteria are subjective, and because of the lack of reproducibility, this histologic point is of limited clinical relevance.
The immunophenotype is that of a mature surface Ig+ B-cell, and both CD19 and CD20 are expressed.
CD10 is positive. BCL-2 expression is not present. TdT expression is lacking.
rapidly replicating large cell lymphomas
Most common in children (1/3 of lymphomas).
3-4% of all lymphomas in adults in western countries
frequently associated with immunodeficiency in adults
endemic variant affecting africans, which primarily involves the jaws and other facial bones.
non-endemic variant may be associated with immunodeficiency and usually presents with abdominal involvement (distal ileum, ciecum, mesentery).
monomorphic infiltrate of the lymph node by medium-sized cells showing round nuclei with several nucleoli and basophilic cytoplasm.
numerous benign macrophages confer a histologic pattern referred to as ’starry sky’ apparance.
Involvement of the peripheral blood and bone marrow may occur.
Pan-B antigens positive (CD19+, CD20+, CD22+)
CD38+, CD77+, CD43+
BCL2- or BCL2+/- (20%)
sIgM+ (membrane IgM)
blast cells in the peripheral blood and bone marrow display a basophilic cytoplasm with characteristic vacuolization.
- This aspect is indisinguishable from acute lymphoblastic leukemia (ALL) L3 of the FAB classification, which represents the leukemic counterpart of BL.
B lymphoblastic lymphoma
nodal Burkitt lymphoma
intestinal Burkitt lymphoma
- ileal Burkitt lymphoma
bilateral mammary Burkitt lymphoma (7761167)
- PTLD monotypic Burkitt lymphoma type (12766587)
The related form Burkitt-like lymphoma shows intermediate features between diffuse large cell lymphoma and Burkitt lymphoma and probably includes different disease entities.
- It was suggested by the WHO panel that only those cases with c-MYC rearrangeme+nt and/or a >99% proliferation fraction as demonstrated by Ki-67 positivity should be classified as Burkitt-like lymphoma.
Cytogenetic analyses play a key role in conﬁ rming the diagnosis.
FISH studies are very helpful in demonstrating translocations that deregulate expression of the protooncogene c-myc (chromosome 8) paired with either the heavy-chain loci (chromosome 14) or light-chain locus (chromosome 2 and 22).
8q24 rearrangements (MYC locus)
- translocation t(8;14)(q24;q32) (MYC/IGH) (60-70%)
- translocation t(8;22)(q24;q11) (MYC/) (10-15%)
- translocation t(2;8)(p11;q24) (MYC/) (2-5%)
Most chromosomal t(8;14) translocations in sporadic Burkitt lymphomas (BL) are mediated by immunoglobulin class switch recombination (CSR), yet all tumors express IgM, suggesting an incomplete or exclusively monoallelic CSR event. (16736499)
- duplication of chromosome 1, involving the 1q21-25 segment as the only detectable chromosome lesion
- 6q11-14 deletion
- 17p deletions (TP53 inactivation)
- trisomy 12, trisomy 7, trisomy 8 and trisomy 18
Gong JZ, Stenzel TT, Bennett ER, Lagoo AS, Dunphy CH, Moore JO, Rizzieri DA, Tepperberg JH, Papenhausen P, Buckley PJ. Burkitt lymphoma arising in organ transplant recipients: a clinicopathologic study of five cases. Am J Surg Pathol. 2003 Jun;27(6):818-27. PMID: 12766587