Burkitt Lymphoma
Lessons From the Friday Unknowns
Histological sections show an enlarged lymph node effaced by a neoplastic lymphocytic proliferation with frequent mitotic figures and numerous tingible body macrophages imparting a “starry sky” pattern. Extensive extra capsular extension into the surrounding adipose tissue is noted.
The lymphoma cells are composed of monotonous medium sized cells with rounded nuclei, fine clumped chromatin, and basophilic scant cytoplasm. Extensive extra capsular extension into the surrounding adipose tissue is noted.
Immunohistochemical studies demonstrate that the lymphoma cells are positive for CD10, CD20, PAX5 and BCL6 expression. The lymphoma cells are negative for MUM1 and BCL-2 expression. The lymphoma shows a high Ki-67 proliferation index (> 95%).