HGBL DH/TH are aggressive mature B cell lymphomas with variable morphology, ranging from pleomorphic large cells to medium-sized cells with features intermediate between DLBCL and Burkitt lymphoma (BCLU), to blastoid cells (Fig. 1), where FISH analyses identify MYC gene rearrangement in association with BCL2 and/or BCL6 gene rearrangements (Fig. 2). Here, BCL6 is linked to Burkitt lymphoma.