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.[1]
- Non-endemic:
- Typical of the BL seen in the western world; EBV negative.
- Immunodeficiency associated:
- Associated with HIV infection.
Pathophysiology
- Origin cell: germinal centre B cells (favoured) vs. memory B cells.[1]
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.
- The stars in the pattern are: tingible-body macrophages.
- Tumour cells:[1]
- 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.
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.[1]