Burkitt lymphoma

From Libre Pathology
Revision as of 05:00, 22 February 2012 by Michael (talk | contribs) (→‎Microscopic)
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:

DDx:

  • DLBCL.
  • B cell lymphoma unclassifiable with features intermediate between DLBCL and Burkitt lymphoma.[3]

Cytology

Features:

  • Medium-sized lymphoid cells with small lipid vacuoles (~1-2 micrometers).[4]

Image:

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.
  3. Carbone, A.; Gloghini, A.; Aiello, A.; Testi, A.; Cabras, A. (May 2010). "B-cell lymphomas with features intermediate between distinct pathologic entities. From pathogenesis to pathology.". Hum Pathol 41 (5): 621-31. doi:10.1016/j.humpath.2009.10.027. PMID 20398809.
  4. Troxell, ML.; Bangs, CD.; Cherry, AM.; Natkunam, Y.; Kong, CS. (Oct 2005). "Cytologic diagnosis of Burkitt lymphoma.". Cancer 105 (5): 310-8. doi:10.1002/cncr.21307. PMID 15986398.