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CASE REPORT article

Front. Oncol.

Sec. Hematologic Malignancies

Volume 15 - 2025 | doi: 10.3389/fonc.2025.1508676

This article is part of the Research TopicHost Features Affecting CAR T Cell Therapy of Hematological MalignanciesView all 3 articles

Extramedullary Relapse of Acute Lymphoblastic Leukemia Treated with a CAR-T Cell Therapy Bridge to Unrelated Cord Blood Transplantation: A Case Report and Review of the Literature

Provisionally accepted
Huibo  LiHuibo Li1Jie  LiuJie Liu1Dan  GuoDan Guo1Yanqiu  ZhaoYanqiu Zhao1Qi  LiQi Li1Sen  QiSen Qi1Jinxiao  HouJinxiao Hou2Zhang  Jian-pingZhang Jian-ping3Shengjin  FanShengjin Fan1*
  • 1Department of Hematology, First Affiliated Hospital of Harbin Medical University, Harbin, China
  • 2Department of Hematology, The Second Hospital of Anhui Medical University, Hefei, Anhui Province, China
  • 3Department of bone marrow transplantation, HeBei Yanda Lu Daopei Hospital, Langfang, Hebei Province, China

The final, formatted version of the article will be published soon.

Extramedullary relapse of acute lymphoblastic leukemia (ALL) is usually associated with poor prognosis. Chimeric antigen receptor T cell (CAR-T cell) therapy followed by allogeneic hematopoietic stem cell transplantation is beneficial for relapsed/refractory (r/r) B cell acute lymphoblastic leukemia (B-ALL). Here, we report a B-ALL patient with extramedullary relapse involving several organs, including multiple lymph nodes and the breast, kidney, uterus and pancreas. After treatment with CAR-T cell therapy, positron emission tomography/computed tomography (PET/CT) revealed that she went into remission, with an almost undetectable tumor mass. She subsequently received unrelated cord blood transplantation (UCBT). Although she achieved minimal residual disease (MRD)-negative remission after UCBT for 5 months, she relapsed at the 6th month after UCBT. This patient achieved remission after subsequent interferon-α treatment for two weeks but eventually died of severe pneumonia. This case highlights the possibility of unusual relapse sites after chemotherapy and that regular biopsy of the mass is not sufficient to assess the scope and location of recurrence. PET/CT may be a useful tool to monitor the scope of extramedullary recurrence and follow-up remission.Further understanding of the pathology of extramedullary relapse is warranted to improve the management of such challenging presentations. This case suggests the efficacy of CAR-T cell therapy combined with UCBT in adult B-ALL patients with extramedullary relapse.

Keywords: Extramedullary relapse, Acute Lymphoblastic Leukemia, Chimeric antigen receptor T cell, Unrelated cord blood transplantation, PET/CT

Received: 09 Oct 2024; Accepted: 24 Jul 2025.

Copyright: © 2025 Li, Liu, Guo, Zhao, Li, Qi, Hou, Jian-ping and Fan. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Shengjin Fan, Department of Hematology, First Affiliated Hospital of Harbin Medical University, Harbin, China

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