Transformation of FL into DLBCL with a PMBL gene expression signature

Tristan Loveday, Gerben Duns, Lisa M. Rimsza, Karen L. Rech, James R. Cook, Ryan S. Robetorye, Allison C. Rosenthal, Colleen A. Ramsower, Tameson K. Yip, Catherine L. McKinney, Steven H. Swerdlow, Shweta Bhavsar, Christian Steidl, Sarah E. Gibson

Research output: Contribution to journalArticlepeer-review


We investigated the clinicopathologic features of 5 follicular lymphomas (FLs) that transformed (tFL) morphologically to diffuse large B-cell lymphomas (DLBCLs) and had a primary mediastinal large B-cell lymphoma (PMBL)-like gene expression profile (tFL-PMBLsig-pos). None of the tFL-PMBLsig-pos cases arose in the mediastinum, all cases tested had a germinal center B-cell phenotype, 20% were CD30+, 60% CD23+, 80% MAL+, 20% CD200+, and 0% CD273/PDL2+. Whole-exome sequencing detected alterations in genes associated with both FL/DLBCL (CREBBP, KMT2C, KMT2D, ARID1A, HIST1 members, and TNFRSF14) and PMBL (JAK-STAT pathway genes, B2M, and CD58). Copy number (CN) analysis detected gains/amplification of REL and STAT6 in 60%, gains of SOCS1 in 40%, and gains of chromosome 16, including IL4R, in 40% of the cases. CN gains/amplification of BCL6 and MYC and loss of TNFRSF14 and TNFAIP3 were identified in 20% of the cases. Three of 5 cases lacked a BCL2 rearrangement. Despite having some features that are less common in DLBCL (MAL and CD23 expression and JAK-STAT activation), these tFL-PMBLsig-pos cases lack the most characteristic CN alteration seen in PMBL (9p24.1 gain/amplification). This cohort expands the biologic heterogeneity of tFL, illustrating a subset with gene expression and some genetic features reminiscent of PMBL, with potential treatment implications that include the use of novel targeted therapies.

Original languageEnglish (US)
Pages (from-to)893-899
Number of pages7
JournalBlood Advances
Issue number6
StatePublished - Mar 28 2023

ASJC Scopus subject areas

  • Hematology


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