{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T05:23:22Z","timestamp":1787289802509,"version":"build-2736575974"},"reference-count":16,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T00:00:00Z","timestamp":1787270400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Med."],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Collision hematologic malignancies, characterized by the concurrent presence of clonally independent myeloid and lymphoid neoplasms within a single patient, are exceptionally uncommon. Diagnosing these malignancies is particularly challenging when they occur in the context of chronic inflammatory diseases, where distinguishing between reactive and neoplastic processes is complex.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Case presentation<\/jats:title>\n                    <jats:p>\n                      We present the case of a 66-years-old male patient with COPD, characterized by a 30 pack-year smoking history, who was admitted due to an acute exacerbation of COPD (AECOPD) accompanied by fever. Notably, despite the complete normalization of C-reactive protein (CRP &amp;lt; 0.2 mg\/L), there was a paradoxical increase in the white blood cell (WBC) count to 50.2 \u00d7 10\n                      <jats:sup>9<\/jats:sup>\n                      \/L during treatment with high-dose intravenous methylprednisolone. Concurrently, the absolute lymphocyte count rose to 8.08 \u00d7 10\n                      <jats:sup>9<\/jats:sup>\n                      \/L, a phenomenon we describe as \u201cclinico-laboratory dissociation.\u201d This atypical kinetic pattern prompted further hematologic work-up, including bone marrow evaluation, which revealed the coexistence of chronic-phase chronic myeloid leukemia (CML) [BCR::ABL1 IS: 64.93%; t(9;22)(q34;q11.2)] and chronic lymphocytic leukemia (CLL)-like monoclonal B-cell lymphocytosis (MBL) [CD19\n                      <jats:sup>+<\/jats:sup>\n                      CD5\n                      <jats:sup>+<\/jats:sup>\n                      CD23\n                      <jats:sup>+<\/jats:sup>\n                      CD20(dim), \u03ba-restricted, monoclonal IGH rearrangement]. During the diagnostic process, the patient developed life-threatening\n                      <jats:italic>Pneumocystis jirovecii<\/jats:italic>\n                      pneumonia (PJP), confirmed through sputum PCR. The patient received treatment with imatinib (400 mg\/day) and high-dose trimethoprim-sulfamethoxazole (TMP-SMX, 15\u201320 mg\/kg\/day), resulting in the resolution of respiratory symptoms within 1 week and an early molecular response by day 21, as evidenced by a reduction in BCR::ABL1 IS from 64.93% to 11.03%.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>In this patient with COPD undergoing systemic corticosteroid treatment, steroid-resistant lymphocytosis accompanied by WBC\u2013CRP dissociation led to a bone marrow evaluation that revealed two concurrent clonal hematologic disorders. This single case suggests that such a pattern may warrant hematologic assessment in similar clinical settings, and that even subclinical clonal B-cell disorders may carry immunological relevance meriting further study, though this observation requires validation in larger cohorts before informing clinical practice.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fmed.2026.1872985","type":"journal-article","created":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T04:23:09Z","timestamp":1787286189000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Concurrent CML and MBL in a COPD patient: a case of collision hematologic malignancies and opportunistic infection"],"prefix":"10.3389","volume":"13","author":[{"given":"Liang","family":"Zhang","sequence":"first","affiliation":[{"name":"Department of Clinical Laboratory, First People\u2019s Hospital of Linping District, Hangzhou","place":["Zhejiang, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mei ying","family":"Zhang","sequence":"additional","affiliation":[{"name":"Department of Pathology, Adicon Medical Laboratory Co., Ltd., Hangzhou","place":["Zhejiang, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chang sheng","family":"Zhou","sequence":"additional","affiliation":[{"name":"Departments of Respiratory and Critical Care Medicine, The People\u2019s Hospital of Cangnan Zhejiang, Wenzhou","place":["Zhejiang, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xing yuan","family":"Ci","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory, First People\u2019s Hospital of Linping District, Hangzhou","place":["Zhejiang, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Long ying","family":"Zhu","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory, First People\u2019s Hospital of Linping District, Hangzhou","place":["Zhejiang, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qi lei","family":"Hu","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory, First People\u2019s Hospital of Linping District, Hangzhou","place":["Zhejiang, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhi rong","family":"Qi","sequence":"additional","affiliation":[{"name":"Department of Integrative Oncology, China-Japan Friendship Hospital","place":["Beijing, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shui","family":"Fu","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory, First People\u2019s Hospital of Linping District, Hangzhou","place":["Zhejiang, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zuo jie","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory, The People\u2019s Hospital of Cangnan Zhejiang, Wenzhou","place":["Zhejiang, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,8,21]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"1702","DOI":"10.1038\/s41375-025-02635-1","article-title":"Predisposition to hematopoietic malignancies by deleterious germline CHEK2 variants.","volume":"39","author":"Stubbins","year":"2025","journal-title":"Leukemia"},{"key":"B2","doi-asserted-by":"publisher","first-page":"1921","DOI":"10.1038\/s41591-021-01521-4","article-title":"Distinction of lymphoid and myeloid clonal hematopoiesis.","volume":"27","author":"Niroula","year":"2021","journal-title":"Nat Med."},{"key":"B3","doi-asserted-by":"publisher","first-page":"309","DOI":"10.4046\/trd.2023.0165","article-title":"Clonal hematopoiesis of indeterminate potential is associated with current smoking status and history of exacerbation in patients with chronic obstructive pulmonary disease.","volume":"87","author":"Lee","year":"2024","journal-title":"Tuberc Respir Dis"},{"key":"B4","doi-asserted-by":"publisher","first-page":"357","DOI":"10.1182\/blood.2021013531","article-title":"Association of clonal hematopoiesis with chronic obstructive pulmonary disease.","volume":"139","author":"Miller","year":"2022","journal-title":"Blood"},{"key":"B5","doi-asserted-by":"publisher","first-page":"195","DOI":"10.1038\/s41408-025-01385-8","article-title":"CHIP amplifies the risk of lymphoid malignancies in individuals with monoclonal B-cell lymphocytosis (MBL).","volume":"15","author":"Boddicker","year":"2025","journal-title":"Blood Cancer J"},{"key":"B6","doi-asserted-by":"publisher","first-page":"167","DOI":"10.1016\/j.bjhh.2017.02.004","article-title":"Concomitant chronic myeloid leukemia and monoclonal B cell lymphocytosis - 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