Double-Hit and Triple-Hit Lymphomas: New Perspectives for Their Classification

Abstract

In 2016, an update on the classification of lymphoid neoplasm was published, and one of the modifications made focussed on B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Burkitt’s lymphoma, a term which has now been abandoned. This represented a very difficult disease in the diagnostic routine of pathologists. The new proposed term is high-grade B-cell lymphoma, which includes the double-hit lymphomas. Yet, there was still confusion about the diagnostic criteria. This review discusses the changes in classification, with an emphasis on the double-hit lymphomas. Diffuse large B-cell lymphoma and Burkitt’s lymphoma are also commented on in the text. The diagnosis of double-hit lymphomas is dependent on molecular tests and it is not available throughout the world. Research identifying features that can allow patients to be specifically selected for these molecular tests is also important.