Cytomorphologic, immunophenotypic, and cytogenetic spectrum in a MYC/BCL2 double-hit high-grade B-cell lymphoma

Abstract

A man in his seventies presented with a bulky abdominal tumor. The level of lactate dehydrogenase was 3,854 U/L, uric acid was 11.1 mg/dL, and soluble interleukin-2 receptor was 5,750 U/mL (reference range, 145 to 519 U/mL). The bone marrow (BM) was infiltrated with large cells with features of Burkitt lymphoma, whereas lymphoma cells in the peripheral blood (PB) exhibited indolent cytomorphology indicative of follicular lymphoma (FL). Multicolor flowcytometry and fluorescence in situ hybridization revealed that BM lymphoma cells were CD10⁺, CD24^bright, and CD38^bright and had t(14;18)(q32;q21)/BCL2-IGH and t(8;14)(q24;q32)/MYC-IGH. In contrast, the majority of PB lymphoma cells were small to medium sized and CD10⁻, CD24^−/dim, and CD38⁻ and had t(14;18)/BCL2-IGH but lacked t(8;14)/MYC-IGH, and we identified a intermediate population composed of medium-sized cells that were CD10^dim, CD24^dim/+, and CD38⁺ and had both t(14;18)/BCL2-IGH and t(8;14)/MYC-IGH. Multiplex polymerase chain reaction confirmed that BM and PB lymphoma cells shared common IGK rearrangement and BCL2-IGH fusion sequence. It is indicated that, in this case, indolent FL and MYC/BCL2 double-hit high-grade B-cell lymphoma (HGBL) transformed from FL developed concurrently and acquisition of t(8;14)/MYC-IGH may not immediately lead to transformation to HGBL, but instead, florid cytomorphologic transformation may occur in BM.