HGBL/DLBCL
Lessons From the Friday Unknowns
Histologic sections show core needle shaped fragments of tissue involved by lymphoma. The neoplasm is diffuse and composed of large lymphoma cells.
Immunohistochemical studies were performed elsewhere and show that the tumor cells are positive for CD20, PAX-5, BCL-2 (strong, 100%), BCL-6, MUM1 and MYC (50–60%) and are negative for CD3, CD21, SOX11, and cyclin D1. CD30 is positive in rare cells, about 1%. Ki-67 shows a proliferation rate of 80%. EBER is negative. CD21 highlights few areas with residual networks of follicular dendritic cells.
Flow cytometry shows a monoclonal B cell population, kappa light chain restricted, positive for CD10. No further information of the phenotype of the tumor cells is provided. Also, per report FISH studies revealed the presence of MYC gene rearrangements, as well as gains of MYC…