{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T05:05:05Z","timestamp":1789967105557,"version":"4.0.1"},"reference-count":7,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T00:00:00Z","timestamp":1789948800000},"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. Oncol."],"abstract":"<jats:p>\n                    Diffuse large B-cell lymphoma (DLBCL) is the most common aggressive non-Hodgkin lymphoma in adults, and papillary thyroid carcinoma (PTC) is the most prevalent type of thyroid malignant tumor. Chronic systemic immune dysregulation, constitutive overactivation of the PI3K\/AKT\/mTOR and NF-\u03baB signaling axes, reshaped immunosuppressive tissue microenvironment and aberrant B-cell clonal expansion serve as core shared molecular and immunological mechanisms that synergistically predispose patients to synchronous tumorigenesis of papillary thyroid carcinoma and ABC-type double-expressing diffuse large B-cell lymphoma. Both are clinically high-incidence malignancies; however, cases with synchronous diagnosis of\n                    <jats:italic>de novo<\/jats:italic>\n                    double primary DLBCL and PTC are extremely rare in clinical practice. Due to potential symptom overlap or lesion location correlation between the two diseases, misdiagnosis and missed diagnosis are likely to occur. Treatment regimens need to take into account the pathophysiological characteristics, clinical staging of both tumors, and the patient\u2019s individual tolerance, leading to high difficulty in clinical decision-making. This article reports a 49-year-old female patient with\n                    <jats:italic>de novo<\/jats:italic>\n                    double primary bilateral PTC (with right cervical lymph node metastasis, metastasis rate 4\/6) and stage I A DLBCL (not otherwise specified, activated B-cell-like subtype, double-expressor). The diagnosis was confirmed by preoperative imaging evaluation, puncture biopsy pathology, as well as postoperative specimen pathology, immunohistochemistry, and fluorescence\n                    <jats:italic>in situ<\/jats:italic>\n                    hybridization (FISH) detection. The patient received radical thyroidectomy combined with polatuzumab vedotin (Pola)-anti-CD20 monoclonal antibody-CHP regimen for immunochemotherapy. Grade III neutropenia occurred during treatment, which returned to normal after symptomatic treatment and secondary prevention, with good tolerance in subsequent treatment. After 6 cycles of immunochemotherapy, DLBCL achieved complete remission (CR), and the patient recovered well after thyroidectomy, completing planned iodine-131 therapy postoperatively. As of October 2025, the total follow-up duration was 6 months, with no signs of tumor recurrence noted to date; nevertheless, longer-term continuous surveillance is still required to definitively exclude late relapse risk, given the aggressive nature of double-expressor DLBCL. Meanwhile, combined with the diagnosis and treatment process of this case and relevant literature, we discuss the clinical characteristics, diagnostic key points, and individualized treatment strategies of double primary DLBCL and PTC, aiming to provide a reference for the standardized diagnosis and treatment of similar rare clinical cases.\n                  <\/jats:p>","DOI":"10.3389\/fonc.2026.1921091","type":"journal-article","created":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T04:28:30Z","timestamp":1789964910000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["A case report and diagnostic-therapeutic analysis of de novo bilateral papillary thyroid carcinoma complicated with stage I a diffuse large B-cell lymphoma (ABC subtype, double-expressor)"],"prefix":"10.3389","volume":"16","author":[{"given":"Lijing","family":"Wang","sequence":"first","affiliation":[{"name":"Department of Hematology, Qilu Hospital of Shandong University Dezhou Hospital","place":["Dezhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yang","family":"Zhou","sequence":"additional","affiliation":[{"name":"Department of Hematology, Qilu Hospital of Shandong University Dezhou Hospital","place":["Dezhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Long","family":"Liu","sequence":"additional","affiliation":[{"name":"Department of Hematology, Qilu Hospital of Shandong University Dezhou Hospital","place":["Dezhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jinfeng","family":"Tian","sequence":"additional","affiliation":[{"name":"Department of Hematology, Qilu Hospital of Shandong University Dezhou Hospital","place":["Dezhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhengyao","family":"Zhang","sequence":"additional","affiliation":[{"name":"Department of Hematology, The Affiliated Taian City Central Hospital of Qingdao University","place":["Taian, Shandong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ziyi","family":"Shao","sequence":"additional","affiliation":[{"name":"Medical School, Shandong Xiehe University","place":["Jinan, Shandong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jingfei","family":"Shi","sequence":"additional","affiliation":[{"name":"Department of Clinical and Basic Medicine, Shandong First Medical University","place":["Jinan, Shandong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shumei","family":"Liu","sequence":"additional","affiliation":[{"name":"Department of Hematology, Qilu Hospital of Shandong University Dezhou Hospital","place":["Dezhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chao","family":"Cui","sequence":"additional","affiliation":[{"name":"Scientific Research Department, Qilu Hospital of Shandong University Dezhou Hospital","place":["Dezhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,21]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1182\/blood.2024024788","article-title":"How I treat older patients with relapsed\/refractory diffuse large B-celllymphoma","volume":"145","author":"Wallace","year":"2025","journal-title":"Blood"},{"key":"B2","doi-asserted-by":"publisher","first-page":"100819","DOI":"10.1016\/j.patol.2025.100819","article-title":"Papillary thyroid carcinoma with fibromatosis\/fasciitis-like\/desmoid-type stroma: When to suspect and how to diagnose","volume":"58","author":"Gonz\u00e1lez-L\u00f3pez","year":"2025","journal-title":"Rev Esp Patol"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1016\/j.radcr.2025.03.029","article-title":"Coexistence of primary diffuse large B-cell lymphoma and papillary thyroidcarcinoma in a patient with Hashimoto's thyroiditis: A case report","volume":"20","author":"Hou","year":"2025","journal-title":"Radiol Case Rep"},{"key":"B4","doi-asserted-by":"publisher","first-page":"14110","DOI":"10.3390\/ijms241814110","article-title":"The role of mTOR in B cell lymphoid Malignancies: Biologic and therapeutic aspects","volume":"24","author":"Karatrasoglou","year":"2023","journal-title":"Int J Mol Sci"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.14740\/jocmr2480w","article-title":"Signaling pathways in thyroid cancer and their therapeutic implications","volume":"8","author":"Jin","year":"2016","journal-title":"J Clin Med Res"},{"key":"B6","doi-asserted-by":"publisher","first-page":"64","DOI":"10.1016\/j.ccell.2016.12.003","article-title":"Simultaneous inhibition of PI3Kdelta and PI3Kalpha induces ABC-DLBCL regression by blocking BCR-dependent and -independent activation of NF-kappaB and AKT","volume":"31","author":"Paul","year":"2017","journal-title":"Cancer Cell"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1200\/JCO-25-00925","article-title":"Five-year outcomes ofthe POLARIX study comparing Pola-R-CHP and R-CHOP in patients with diffuse large B-cell lymphoma","volume":"43","author":"Morschhauser","year":"2025","journal-title":"J Clin Oncol"}],"container-title":["Frontiers in Oncology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fonc.2026.1921091\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T04:28:31Z","timestamp":1789964911000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fonc.2026.1921091\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,21]]},"references-count":7,"alternative-id":["10.3389\/fonc.2026.1921091"],"URL":"https:\/\/doi.org\/10.3389\/fonc.2026.1921091","relation":{},"ISSN":["2234-943X"],"issn-type":[{"value":"2234-943X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,21]]},"article-number":"1921091"}}