{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,10]],"date-time":"2026-10-10T03:53:14Z","timestamp":1791604394554,"version":"4.3.4"},"reference-count":16,"publisher":"Wiley","issue":"4","license":[{"start":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T00:00:00Z","timestamp":1785283200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"},{"start":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T00:00:00Z","timestamp":1785283200000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["eJHaem"],"published-print":{"date-parts":[[2026,8]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Composite indolent B\u2010cell lymphomas may remain unrecognized when one component dominates the clinical presentation. Apparent relapse after therapy may, therefore, represent the emergence of a biologically distinct lymphoma rather than the recurrence of the original disease.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Case Presentation<\/jats:title>\n                    <jats:p>\n                      An 82\u2010year\u2010old woman presented with systemic low\u2010grade B\u2010cell lymphoma that was most consistent with marginal zone lymphoma (MZL). Staging demonstrated peripheral blood involvement and multifocal FDG\u2010avid disease. Treatment with the CD20\u00d7CD3\u2010bispecific antibody mosunetuzumab resulted in complete metabolic remission. During surveillance, a new, isolated cervical lymph node developed despite sustained systemic response. Biopsy revealed follicular lymphoma (Grade 1\u20132) with a germinal center phenotype and a\n                      <jats:italic>BCL2<\/jats:italic>\n                      rearrangement, findings discordant with recurrence of MZL. Retrospective review of the original specimen identified in situ follicular neoplasia within the initial biopsy. The disease course was, therefore, reinterpreted as a synchronous composite lymphoma in which treatment of the dominant MZL unmasked a previously clinically silent B\u2010cell neoplasm with follicular lineage. Local radiotherapy achieved remission of the follicular component.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>New disease following treatment of an indolent lymphoma should not automatically be interpreted as relapse. Discordant clinical behavior, particularly focal progression after systemic response, warrants repeat biopsy and integrated pathologic reassessment. This case illustrates how therapy may reveal preexisting clonal heterogeneity and emphasizes the importance of temporality in distinguishing relapse from composite lymphoma.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Trial Registration<\/jats:title>\n                    <jats:p>The authors have confirmed clinical trial registration is not needed for this submission<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1002\/jha2.70370","type":"journal-article","created":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T16:35:22Z","timestamp":1785342922000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Unmasking a Composite Lymphoma: Follicular Lymphoma Emerging After Bispecific Antibody Treatment of Marginal Zone Lymphoma"],"prefix":"10.1002","volume":"7","author":[{"given":"Angel Luis","family":"Orosco\u2010Ttamina","sequence":"first","affiliation":[{"name":"Division of Hematology and Oncology Department of Internal Medicine Mayo Clinic  Phoenix Arizona USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiehao","family":"Zhou","sequence":"additional","affiliation":[{"name":"Department of Pathology and Laboratory Medicine Mayo Clinic  Phoenix Arizona USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Juliana","family":"Biondo","sequence":"additional","affiliation":[{"name":"Genentech, Inc.  South San Francisco California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Farah","family":"Hossain","sequence":"additional","affiliation":[{"name":"Genentech, Inc.  South San Francisco California USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David","family":"Viswanatha","sequence":"additional","affiliation":[{"name":"Department of Pathology and Laboratory Medicine Mayo Clinic  Rochester Minnesota USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Patricia T.","family":"Greipp","sequence":"additional","affiliation":[{"name":"Department of Pathology and Laboratory Medicine Mayo Clinic  Rochester Minnesota USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Natasha","family":"Lewis","sequence":"additional","affiliation":[{"name":"Department of Pathology and Laboratory Medicine Mayo Clinic  Phoenix Arizona USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Javier","family":"Munoz","sequence":"additional","affiliation":[{"name":"Division of Hematology and Oncology Department of Internal Medicine Mayo Clinic  Phoenix Arizona USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,7,29]]},"reference":[{"key":"e_1_2_11_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0140\u20106736(23)02705\u20108"},{"key":"e_1_2_11_3_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41375\u2010022\u201001620\u20102"},{"key":"e_1_2_11_4_1","doi-asserted-by":"publisher","DOI":"10.1182\/blood.2022015851"},{"key":"e_1_2_11_5_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00428\u2010022\u201003432\u20102"},{"key":"e_1_2_11_6_1","doi-asserted-by":"publisher","DOI":"10.1002\/path.6143"},{"key":"e_1_2_11_7_1","doi-asserted-by":"publisher","DOI":"10.1002\/path.5861"},{"key":"e_1_2_11_8_1","doi-asserted-by":"publisher","DOI":"10.3324\/haematol.2020.254854"},{"key":"e_1_2_11_9_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jmoldx.2021.06.005"},{"key":"e_1_2_11_10_1","doi-asserted-by":"publisher","DOI":"10.1182\/bloodadvances.2023010840"},{"key":"e_1_2_11_11_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.clml.2025.10.010"},{"key":"e_1_2_11_12_1","doi-asserted-by":"publisher","DOI":"10.1182\/bloodadvances.2025016315"},{"key":"e_1_2_11_13_1","doi-asserted-by":"publisher","DOI":"10.1182\/blood.2024025355"},{"key":"e_1_2_11_14_1","doi-asserted-by":"publisher","DOI":"10.3390\/cancers17020317"},{"key":"e_1_2_11_15_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.humpath.2013.02.004"},{"key":"e_1_2_11_16_1","doi-asserted-by":"publisher","DOI":"10.1200\/JCO.2013.53.5229"},{"key":"e_1_2_11_17_1","doi-asserted-by":"publisher","DOI":"10.1182\/blood.2025029117"}],"container-title":["eJHaem"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/jha2.70370","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1002\/jha2.70370","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/jha2.70370","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,10]],"date-time":"2026-10-10T03:42:55Z","timestamp":1791603775000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/jha2.70370"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,29]]},"references-count":16,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2026,8]]}},"alternative-id":["10.1002\/jha2.70370"],"URL":"https:\/\/doi.org\/10.1002\/jha2.70370","archive":["Portico"],"relation":{},"ISSN":["2688-6146","2688-6146"],"issn-type":[{"value":"2688-6146","type":"print"},{"value":"2688-6146","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,29]]},"assertion":[{"value":"2026-04-07","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-06-25","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-07-29","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e70370"}}