Burkitt lymphoma

From Libre Pathology
Jump to navigation Jump to search

Burkitt lymphoma, abbreviated BL, is an uncommon lymphoma with medium-sized cells.

General

  • Extremely high proliferative rate & rate of apoptosis.
  • Rare in adults -- 1-2% of adult lymphomas.[1]
  • Relatively common in children -- 30-50% of childhood lymphomas.[1]

Pathophysiology

  • Origin cell: germinal centre B cells (favoured) vs. memory B cells.[2]

Subtypes

  • Three subtypes recognized:[2]
  1. Endemic:
  2. Non-endemic:
    • Typical of the BL seen in the western world; EBV negative.
  3. Immunodeficiency associated:
    • Associated with HIV infection.

Microscopic

Features:

  • "Starry-sky pattern":
    • The stars in the pattern are: tingible-body macrophages.
      • Tingible-body macrophages = macrophages containing apoptotic tumour cells.
    • The tumour cells are the sky.
  • Tumour cells:[2]
    • Medium-sized (~1.5-2x the size of a RBC) with uniform size ("monotonous") -- key feature.
    • Round nucleus.
    • Small nucleoli.
    • Relatively abundant cytoplasm.
    • Brisk mitotic rate.

Images:

IHC

Features:

  • CD20 +ve.
  • CD10 +ve.
  • BCL6 +ve.
  • EBER +ve.

Others:

  • BCL2 -ve.

Cytologic definition

  • t(8;14) (q24;q32) translocation.[2]
  • Several other variants -- involve MYC rearrangement.[2][1]

Note:

  • MYC rearrangement is typically assessed with an ISH break apart probe.

See also

References

  1. 1.0 1.1 1.2 Online 'Mendelian Inheritance in Man' (OMIM) 113970
  2. 2.0 2.1 2.2 2.3 2.4 2.5 Bellan C, Lazzi S, De Falco G, Nyongo A, Giordano A, Leoncini L (March 2003). "Burkitt's lymphoma: new insights into molecular pathogenesis". J. Clin. Pathol. 56 (3): 188–92. PMC 1769902. PMID 12610094. http://jcp.bmj.com/cgi/pmidlookup?view=long&pmid=12610094.