{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T05:55:07Z","timestamp":1790747707868,"version":"4.1.0"},"reference-count":23,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T00:00:00Z","timestamp":1790726400000},"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>Intrathyroidal thymic carcinoma (ITTC) with neuroendocrine differentiation is rare, and evidence for definitive radiotherapy in nonsurgical patients remains limited. A 70-year-old woman with a 1-year history of a neck mass and hoarseness was diagnosed with ITTC with neuroendocrine differentiation based on histopathological, immunohistochemical, and imaging findings. After declining surgery and systemic chemotherapy, she received definitive radiotherapy: 60 Gy in 30 fractions to the planning target volume, followed by a sequential boost of 6 Gy in 3 fractions to the gross primary tumor and involved lymph nodes, for a cumulative dose of 66 Gy in 33 fractions. No grade \u22653 acute treatment-related toxicities occurred. At approximately 2 months after radiotherapy, the sum of target-lesion diameters decreased from 54\u00a0mm to 42\u00a0mm, a 22.2% reduction. With no new lesions or unequivocal progression of non-target disease, the overall response was classified as stable disease according to RECIST 1.1. This case documents early radiographic tumor reduction following definitive radiotherapy for ITTC, although longer follow-up is required to assess the durability of disease control and late toxicity.<\/jats:p>","DOI":"10.3389\/fonc.2026.1944330","type":"journal-article","created":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T04:56:44Z","timestamp":1790744204000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Case Report: Definitive radiotherapy for intrathyroidal thymic carcinoma with neuroendocrine differentiation"],"prefix":"10.3389","volume":"16","author":[{"given":"Jia","family":"Du","sequence":"first","affiliation":[{"name":"The First Clinical Medicine College, Gansu University of Chinese Medicine","place":["Lanzhou, China"]},{"name":"Department of Radiotherapy, Gansu Provincial Hospital","place":["Lanzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiankai","family":"Wang","sequence":"additional","affiliation":[{"name":"Department of Radiotherapy, Gansu Provincial Hospital","place":["Lanzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jianbing","family":"Song","sequence":"additional","affiliation":[{"name":"The First Clinical Medicine College, Gansu University of Chinese Medicine","place":["Lanzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yunzhi","family":"Xu","sequence":"additional","affiliation":[{"name":"The First Clinical Medicine College, Gansu University of Chinese Medicine","place":["Lanzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiaoyu","family":"Duan","sequence":"additional","affiliation":[{"name":"Department of Radiotherapy, Gansu Provincial Hospital","place":["Lanzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hongyi","family":"Cai","sequence":"additional","affiliation":[{"name":"Department of Radiotherapy, Gansu Provincial Hospital","place":["Lanzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,30]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1007\/s12022-022-09708-2","article-title":"Overview of the 2022 WHO classification of neuroendocrine neoplasms","volume":"33","author":"Rindi","year":"2022","journal-title":"Endocr Pathol"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1007\/s00423-025-03920-4","article-title":"ABO blood group and Rhesus factor as potential markers in papillary thyroid cancer: a retrospective comparative analysis (2015-2023)","volume":"411","author":"Aydo\u011fdu","year":"2025","journal-title":"Langenbecks Arch Surg"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.19538\/j.cjps.issn1005-2208.2025.09.20","article-title":"Diagnosis and treatment strategies for intrathyroidal thymic carcinoma [in Chinese","volume":"45","author":"Wang","year":"2025","journal-title":"Chin J Pract Surg"},{"key":"B4","doi-asserted-by":"publisher","first-page":"894","DOI":"10.1002\/lio2.805","article-title":"Genomic variation associated with carcinoma showing thymus-like elements (CASTLE) in thyroid gland","volume":"7","author":"Jiang","year":"2022","journal-title":"Laryngoscope Investig Otolaryngol"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.3390\/life12091314","article-title":"Thyroid carcinoma showing thymus-like differentiation (CASTLE): a case report","volume":"12","author":"Stanciu","year":"2022","journal-title":"Life (Basel)"},{"key":"B6","doi-asserted-by":"publisher","first-page":"593","DOI":"10.1530\/erc-21-0123","article-title":"Outcome of patients with intrathyroidal thymic carcinoma: a pooled analysis","volume":"28","author":"Gurizzan","year":"2021","journal-title":"Endocr Relat Cancer"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.4103\/ijpm.ijpm_232_23","article-title":"Intrathyroidal thymic carcinoma not so indolent a neoplasm","volume":"67","author":"Anila","year":"2024","journal-title":"Indian J Pathol Microbiol"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1507\/endocrj.EJ22-0141","article-title":"Clinicopathological features and outcomes of intrathyroidal thymic carcinoma: a single institution study","volume":"69","author":"Ito","year":"2022","journal-title":"Endocr J"},{"key":"B9","doi-asserted-by":"publisher","first-page":"20","DOI":"10.1186\/s13044-021-00111-3","article-title":"Recurrence of carcinoma showing thymus-like differentiation (CASTLE) involving the thyroid gland","volume":"14","author":"Dang","year":"2021","journal-title":"Thyroid Res"},{"key":"B10","article-title":"Histopathological study of carcinoma showing thymus-like differentiation (CASTLE)","volume":"42","author":"Okubo","year":"2020","journal-title":"Malays J Pathol"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.21037\/gs-2024-540","article-title":"Navigating the rare: a case report of intrathyroidal thymic carcinoma","volume":"14","author":"Wang","year":"2025","journal-title":"Gland Surg"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1309\/AJCP88FZTWANLRCB","article-title":"Thymic carcinoma, part 1: a clinicopathologic and immunohistochemical study of 65 cases","volume":"138","author":"Weissferdt","year":"2012","journal-title":"Am J Clin Pathol"},{"key":"B13","doi-asserted-by":"publisher","first-page":"25090","DOI":"10.14670\/hh-25-090","article-title":"Intrathyroid thymic carcinoma: a comprehensive review of clinicopathological features and therapeutic strategies","volume":"15","author":"Gao","year":"2026","journal-title":"Histol Histopathol"},{"key":"B14","doi-asserted-by":"publisher","first-page":"95","DOI":"10.9738\/intsurg-d-12-00034.1","article-title":"Clinical analysis of thyroid carcinoma showing thymus-like differentiation: report of 8 cases","volume":"98","author":"Liu","year":"2013","journal-title":"Int Surg"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.3389\/fonc.2017.00207","article-title":"CASTLE thyroid tumor: a case report and literature review","volume":"7","author":"Lominska","year":"2017","journal-title":"Front Oncol"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1002\/dc.24281","article-title":"Intrathyroidal thymic carcinoma exhibiting neuroendocrine differentiation: case report with cytomorphology, immunocytochemistry, and review of the literature focusing on cytology","volume":"47","author":"Ren","year":"2019","journal-title":"Diagn Cytopathol"},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.1007\/s13402-020-00505-9","article-title":"Insulinoma-associated protein 1 (INSM1): a potential biomarker and therapeutic target for neuroendocrine tumors","volume":"43","author":"Mahalakshmi","year":"2020","journal-title":"Cell Oncol (Dordr)"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.3760\/cma.j.cn112137-20231008-00676","article-title":"Clinical diagnosis and treatment analysis of 21 cases of intrathyroid thymic carcinoma","volume":"104","author":"Feng","year":"2024","journal-title":"Zhonghua Yi Xue Za Zhi"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.1007\/s00595-013-0560-2","article-title":"Management of thyroid carcinoma showing thymus-like differentiation (CASTLE) invading the trachea","volume":"43","author":"Tsutsui","year":"2013","journal-title":"Surg Today"},{"key":"B20","doi-asserted-by":"publisher","DOI":"10.1002\/bjs.4510","article-title":"Carcinoma showing thymic-like elements--a rare malignancy of the thyroid gland","volume":"91","author":"Roka","year":"2004","journal-title":"Br J Surg"},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.1097\/MD.0000000000044836","article-title":"Chemoradiotherapy as a pivotal therapeutic modality for inoperable intrathymic thyroid carcinoma: a case report and literature review","volume":"104","author":"Huang","year":"2025","journal-title":"Med (Baltimore)"},{"key":"B22","doi-asserted-by":"publisher","DOI":"10.1007\/s00066-021-01800-6","article-title":"Inoperable CASTLE of the thyroid gland treated with radical radiotherapy with complete remission","volume":"197","author":"Kov\u00e1\u0159ov\u00e1","year":"2021","journal-title":"Strahlenther Onkol"},{"key":"B23","doi-asserted-by":"publisher","first-page":"1083","DOI":"10.1186\/s12885-022-10171-9","article-title":"Failure pattern and suggestions for target volume delineation of carcinoma showing thymus-like differentiation treated with intensity-modulated radiotherapy","volume":"22","author":"Kong","year":"2022","journal-title":"BMC Cancer"}],"container-title":["Frontiers in Oncology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fonc.2026.1944330\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T04:56:49Z","timestamp":1790744209000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fonc.2026.1944330\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,30]]},"references-count":23,"alternative-id":["10.3389\/fonc.2026.1944330"],"URL":"https:\/\/doi.org\/10.3389\/fonc.2026.1944330","relation":{},"ISSN":["2234-943X"],"issn-type":[{"value":"2234-943X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,30]]},"article-number":"1944330"}}