<B>Burkitt's Lymphoma </B>

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Burkitt's Lymphoma

Etiology:

• Epstein-Barr virus infection plays a role in African cases

Pathogenesis:

• In EBV associated disease, virus binds CD21 (B cell and oropharyngeal mucosa), forms episomal latent infection without integration
• Cells are immortalized via prevention of apoptosis
• However, the step linking this viral infection to chromosome translocations and malignancy is not clear
• Translocation with breakpoint on chromosome 8 and chromosome 14 (80% both kappa and lambda light chains), 2 (kappa light chains), and 22 (lambda light chains)
• 80% t(8;14)(q24;q32), 20% t(2;8)(p13;q24) or t(8;22)(q24:q11)

Epidemiology:

• African population of predominantly male children between 5 and 10 years living within 15 degrees north or south of the equator
• Extranodal disease: jaw in African cases with peak at 3 years of age around developing molars; abdominal or pelvic organs particularly bowel in US cases

General Gross Description:

• May form large hemorrhagic soft masses

General Microscopic Description:

• Diffuse infiltrate of cells with moderate amount of cytoplasm and round to oval nuclei
• Nuclei contain several prominent nucleoli
• Apoptosis and high mitotic rate obvious
• Numerous tingible body macrophages containing lymphocyte debris are seen scattered throughout giving the low power "starry sky" appearance
• Surface immunoglobulin positive, CD19, CD20, CD22, CD10, CD21 (B cell antigens)

Clinical Correlations:

• Good response to aggressive chemotherapy
• Classified as high grade lymphoma

References:
• Cotran RS, et.al. Robbins Pathologic Basis of Disease 5th edition. W.B. Saunders, , 1994, pp. 640-642, 287-9. • Jaffe ES, Surgical Pathology of the Lymph Nodes and related organs, second edition, W.B. Saunders; , 1995, pp.313-319.