Lymphoplasmacytic lymphoma is a mature B-cell lymphoma with variable plasmacytic differentiation that displays an indolent clinical course. Its transformation to a high-grade B-cell lymphoma may occur uncommonly. Although acquisition of a MYC translocation could result in transformation of a low-grade lymphoma into diffuse large B-cell lymphoma, Burkitt lymphoma, or B-lymphoblastic leukemia, to our knowledge the latter 2 transformations have not been well documented in lymphoplasmacytic lymphoma. We report the case of a 70-year-old woman with a 9-year history of lymphoplasmacytic lymphoma/Waldenström macroglobulinemia who presented with rapid enlargement of a left neck mass and pancytopenia, which was diagnosed as Burkitt lymphoma with extensive bone marrow involvement. A series of histopathologic, molecular, and cytogenetic evaluations proved a cytogenetic evolution including t(8;14)(q24;q32)/MYC-IgH and identical clonal B-cell gene rearrangements from the 2 distinct lymphomas, confirming stage 4 aggressive Burkitt lymphoma arising from lymphoplasmacytic lymphoma.