Burkitt lymphoma

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

General

• Extremely high proliferative rate & rate of apoptosis.

Subtypes

• Three subtypes recognized:

1. Endemic:
   • Found in Africa.
   • EBV (Epstein-Barr virus) associated.
2. Non-endemic:
   • Typical of the BL seen in the western world; EBV negative.
3. Immunodeficiency associated:
   • Associated with HIV infection.

Pathophysiology

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

Microscopic

Features:

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

Image: Starry-sky pattern - Ed Uthman (WC).

IHC

Features:

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

Others:

• BCL2 -ve.

Cytologic definition

• t(8;14) (q24;q32) translocation + a few variants or c-myc rearrangement.

See also

• Lymphoma.
• Haematopathology.