Original ArticlesEpstein-Barr Virus-negative Marginal Zone Lymphoma as an Uncommon Form of Monomorphic Posttransplant Lymphoproliferative DisorderGalera, Pallavi MD*; Flavin, Richard MD, PhD†; Savage, Natasha M. MD‡; Saksena, Annapurna MD*; Gong, Shunyou MD, PhD§; Wang, Huan-You MD, PhD∥; Swan, Niall MBBCh¶; Xi, Liqiang MD*; Raffeld, Mark MD*; Pittaluga, Stefania MD, PhD*; Jaffe, Elaine S. MD*Author Information *Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD †Hematopathology Service, Trinity St. James’s Cancer Institute, St. James’s Hospital and Trinity College ¶Department of Pathology and Laboratory Medicine, St. Vincent’s University Hospital, and UCD School of Medicine, Dublin, Ireland ‡Department of Pathology, Hematology& Hematopathology, Medical College of Georgia at Augusta University, Augusta, GA §Department of Pathology and Laboratory Medicine, Ann and Robert H. Lurie Children’s Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL ∥Department of Pathology, University of California San Diego Health System, La Jolla, CA Present address: Pallavi Galera, MD, Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY. Conflicts of Interest and Source of Funding: This research was supported by the Intramural Research Program of the Center for Cancer Research, National Cancer Institute, National Institutes of Health. The authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article Correspondence: Elaine S. Jaffe, MD, Hematopathology Section, Laboratory of Pathology, National Cancer Institute, Building 10/Room 3S235, 10 Center Drive MSC-1500, Bethesda, MD 20892-1500 (e-mail: [email protected]). The American Journal of Surgical Pathology: October 2020 - Volume 44 - Issue 10 - p 1340-1352 doi: 10.1097/PAS.0000000000001514 Buy Metrics Abstract Monomorphic posttransplant lymphoproliferative disorders have been defined as lymphoid or plasmacytic proliferations that fulfill criteria for one of the B-cell or T/NK-cell neoplasms recognized in immunocompetent hosts in the current WHO Classification. Low-grade B-cell neoplasms have historically been excluded from this category, although rare reports of marginal zone lymphoma (MZL) have been described. We report 9 cases of posttransplant Epstein-Barr virus-negative MZL, all arising in solid organ transplant recipients (4 renal, 3 liver, 1 cardiac, and 1 liver, pancreas, and small bowel). Seven were extranodal MZL of mucosa-associated lymphoid tissue type, all of which had gastrointestinal involvement (4 colon, 1 duodenum, 1 stomach, and 1 oropharynx/base of tongue). Notably, the preferential involvement of intestine distinguishes posttransplant extranodal MZL from sporadic cases. Immunoglobulin light-chain restriction was seen in all cases, with polymerase chain reaction showing a monoclonal pattern in 7 of 8 cases with successful amplification of polymerase chain reaction products. A clonally unrelated recurrence was seen in one case. Next-generation sequencing identified recurrent mutations previously reported in MZL in 3/5 cases. MZL was diagnosed at least 1 year after solid organ transplant (median time to presentation, 84 mo; range, 13 to 108 mo). The median age was 44 (range, 9 to 73 y); the male: female ratio was 5:4. The mean follow-up was 33.4 months, with an indolent clinical course observed. A subset responded to reduction in immunosuppression and anti-CD20 therapy alone. These data support the designation of Epstein-Barr virus-negative MZL as an uncommon form of monomorphic posttransplant lymphoproliferative disorders. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.