What is Burkitt's lymphoma?

Burkitt's lymphoma (BL) has been defined on the basis of its characteristic cytomorphology. Although histologically identical, endemic BL and sporadic BL are distinct clinico-anatomical entities. Their morphological identity probably relates to similar chromosomal translocations in both tumours, resulting in c-myc de-regulation and consequent unrestrained proliferation without differentiation. Similar gene rearrangements are found in a proportion of AIDS-related lymphomas that are predominantly extranodal and have the cytomorphology of BL. The term "Burkitt-like lymphoma" (BLL) has been applied to a group of high-grade B-cell lymphomas that appear morphologically intermediate between BL and centroblastic/immunoblastic lymphomas, as detailed in an accompanying paper in this issue. These tumours do not usually show c-myc gene rearrangements. The association of Burkitt's name with such a disparate group of tumours is confusing and new terminology for sporadic BL, AIDS-related BL and BLL is desirable. It is important that clinico-anatomical features, as well as cytomorphology, should be taken into account in the diagnosis of endemic BL. The origin of a case from tropical Africa does not, in itself, imply that it is endemic BL, even more since the AIDS epidemic in that continent.