46-year-old male underwent excision of an enlarged, indolent lymph node at the jaw.
- The lymph node architecture is destroyed by a monotonous population of loosely arranged intermediate-sized cells (between small lymphocytes and immunoblasts) in a capillary network.
- The cells display round to oval somewhat irregular nuclei with a fine to coarse chromatin and 2-5 prominent nucleoli.
- A moderate amount of weakly basophilic to amphophilic cytoplasm is observed.
- The high mitotic rate is characteristic of this tumor.
- Death of single or groups of cells leads to the concomitant presence of tissue macrophages containing cellular debris. At lower magnification, the so-called “starry sky” pattern can be appreciated which is created by the lightly stained macrophages surrounded by clear spaces.
Three distinct clinical forms of Burkitt lymphoma are distinguished.
1) Endemic Burkitt lymphoma: Burkitt lymphoma is endemic especially in malarious parts of Africa. Typically, tumor cells in virtually all patients harbor the EBV genome.
2) Sporadic Burkitt lymphoma: In the US, Burkitt lymphoma accounts for less than 1% of non-Hodgkin lymphomas in adults, but for about 30% of non-Hodgkin lymphomas in children.
3) Immunodeficiency-associated Burkitt lymphoma: Burkitt Lymphoma accounts for about 20% of all lymphomas in patients with AIDS. It is rarely seen in the setting of other immunodeficiencies. Only 50% of HIV-associated Burkitt lymphomas are positive for EBV.
Extranodal sites are frequently affected (ovaries, bone marrow, GI-tract).
Translocation of the MYC locus on chromosome 8 to the IgH gene on chromosome 14.