{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,6]],"date-time":"2026-01-06T05:28:58Z","timestamp":1767677338182,"version":"3.48.0"},"reference-count":8,"publisher":"SAGE Publications","license":[{"start":{"date-parts":[[2025,6,18]],"date-time":"2025-06-18T00:00:00Z","timestamp":1750204800000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"},{"start":{"date-parts":[[2025,6,18]],"date-time":"2025-06-18T00:00:00Z","timestamp":1750204800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Sage Open Medical Case Reports"],"published-print":{"date-parts":[[2025,12]]},"abstract":"<jats:p>Thoracic SMARCA4-deficient undifferentiated tumor is a recently identified aggressive malignancy characterized by inactivating mutations leading to the loss of SMARCA4 protein expression. First classified in the 2021 World Health Organization Classification of Thoracic Tumors, thoracic SMARCA4-deficient undifferentiated tumor typically presents in men in their fourth to sixth decade of life, often with a history of smoking, though a subset of cases occurs in nonsmokers. We present a rare case of stage IV thoracic SMARCA4-deficient undifferentiated tumor in a 40-year-old male without a smoking history, presenting with spinal metastases. The patient experienced right upper back pain, chest pain, and dyspnea. Imaging revealed a right lung mass, multiple hilar and supraclavicular lymph nodes, and spinal metastases. A computed tomography-guided biopsy of the right lung mass initially suggested small cell carcinoma, but subsequent lymph node excision and expert pathologic review confirmed thoracic SMARCA4-deficient undifferentiated tumor, characterized by rhabdoid morphology and loss of SMARCA4 expression. Treatment included concurrent chemoradiotherapy with cisplatin and etoposide, followed by a regimen of carboplatin, etoposide, and atezolizumab, with maintenance therapy using atezolizumab. Despite complications such as a femoral neck fracture and pancytopenia, imaging showed a reduction in tumor size. This case highlights the diagnostic complexity and treatment approaches for thoracic SMARCA4-deficient undifferentiated tumors.<\/jats:p>","DOI":"10.1177\/2050313x251342982","type":"journal-article","created":{"date-parts":[[2025,6,18]],"date-time":"2025-06-18T04:20:58Z","timestamp":1750220458000},"update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":0,"title":["Thoracic SMARCA4-deficient undifferentiated tumor: A case report in a 40-year-old male without a smoking history"],"prefix":"10.1177","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-4405-1972","authenticated-orcid":false,"given":"Karnik","family":"Soghomonian","sequence":"first","affiliation":[{"name":"Department of Psychiatry, Arrowhead Regional Medical Center, Colton, CA, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ahmad","family":"Ibrahim","sequence":"additional","affiliation":[{"name":"Department of Pathology, Arrowhead Regional Medical Center, Colton, CA, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"179","published-online":{"date-parts":[[2025,6,18]]},"reference":[{"key":"e_1_3_2_2_2","doi-asserted-by":"crossref","unstructured":"CAP TODAY. Thoracic SMARCA4-deficient undifferentiated tumor. CAP TODAY\u2014Pathology\/Laboratory Medicine\/Laboratory Management https:\/\/www.captodayonline.com\/thoracic-smarca4-deficient-undifferentiated-tumor\/ (2024 accessed 19 August 2024).","DOI":"10.23880\/oajco-16000193"},{"key":"e_1_3_2_3_2","volume-title":"WHO classification of tumours: thoracic tumours","author":"Lokuhetty D","year":"2021","unstructured":"Lokuhetty D, White VA, Cree IA. WHO classification of tumours: thoracic tumours. vol. 5. 5th ed. International Agency for Research on Cancer, 2021.","edition":"5"},{"key":"e_1_3_2_4_2","doi-asserted-by":"publisher","DOI":"10.1038\/modpathol.2017.61"},{"issue":"2","key":"e_1_3_2_5_2","first-page":"128","article-title":"Under the microscope: a case report of thoracic SMARCA4-deficient undifferentiated tumor with review of the literature","volume":"40","author":"Mundada M","year":"2024","unstructured":"Mundada M, Mannan KA, Vasu D, et al. Under the microscope: a case report of thoracic SMARCA4-deficient undifferentiated tumor with review of the literature. Turk J Pathol 2024; 40(2): 128\u2013133.","journal-title":"Turk J Pathol"},{"issue":"10","key":"e_1_3_2_6_2","article-title":"SMARCA4-deficient undifferentiated tumor: a rare malignancy with distinct clinicopathological characteristics","volume":"14","author":"Al-Shbool G","year":"2022","unstructured":"Al-Shbool G, Krishnan Nair H. SMARCA4-deficient undifferentiated tumor: a rare malignancy with distinct clinicopathological characteristics. Cureus 2022; 14(10): e30708.","journal-title":"Cureus"},{"key":"e_1_3_2_7_2","doi-asserted-by":"publisher","DOI":"10.21037\/qims-23-1813"},{"key":"e_1_3_2_8_2","doi-asserted-by":"publisher","DOI":"10.1053\/j.semdp.2021.06.001"},{"key":"e_1_3_2_9_2","doi-asserted-by":"publisher","DOI":"10.1159\/000510323"}],"container-title":["Sage Open Medical Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/2050313X251342982","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/full-xml\/10.1177\/2050313X251342982","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/2050313X251342982","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,1,6]],"date-time":"2026-01-06T05:19:51Z","timestamp":1767676791000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/2050313X251342982"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,18]]},"references-count":8,"alternative-id":["10.1177\/2050313X251342982"],"URL":"https:\/\/doi.org\/10.1177\/2050313x251342982","relation":{},"ISSN":["2050-313X","2050-313X"],"issn-type":[{"type":"print","value":"2050-313X"},{"type":"electronic","value":"2050-313X"}],"subject":[],"published":{"date-parts":[[2025,6,18]]},"article-number":"2050313X251342982"}}