double hit B cell lymphoma
A rare and new category of lymphoma that debuted in the 2008 WHO lymphoma classification. These neoplasms are B cell lymphomas with 2 oncogenic translocations and have morphologic and immunologic features between conventional diffuse large B-cell lymphoma–DLBCL and Burkitt’s lymphoma–BL. They are highly aggressive neoplasms for which remission is short-lived at best, despite aggressive chemotherapy.
Molecular pathology These lymphomas have 2 chromosomal rearrangements
Effect MYC rearrangement increases cell proliferation. While MYC-positive cells can be killed (because they proliferate), they become resistant to chemotherapy, and
• BCL2 (or, less commonly, BCL6) rearrangements
Effect BCL2 protein expression renders cells antiapoptotic and more difficult to kill
Synonyms B cell lymphoma unclassifiable with features intermediate between DLBCL and BL–Burkitt lymphoma, dual hit B cell lymphoma
References Journal of Hematopathology (27 May 2012), pp. 1-5