{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,16]],"date-time":"2026-01-16T18:25:46Z","timestamp":1768587946265,"version":"3.49.0"},"reference-count":15,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,1,14]],"date-time":"2026-01-14T00:00:00Z","timestamp":1768348800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100016003","name":"Mie University","doi-asserted-by":"crossref","id":[{"id":"10.13039\/100016003","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Biphenotypic sinonasal sarcoma (BSNS) is a very rare, locally aggressive sarcoma arising in the sinonasal region, initially recognized as low-grade sinonasal sarcoma with neural and myogenic differentiation. Here, we report a case of BSNS extending into the intracranial and intraorbital regions, finally diagnosed by a break-apart fluorescence in situ hybridization (FISH) assay for rearrangements of PAX3. A 50-year-old woman presented with left diplopia and exophthalmos. CT and MRI revealed a large ethmoidal mass with intracranial and intraorbital extension. Since preoperative biopsy suggested a benign tumor, endoscopic endonasal resection was performed while preserving the anterior skull base and intraorbital structures. Postoperative histopathological diagnosis indicated synovial sarcoma, and proton beam therapy with adjuvant chemotherapy was subsequently administered. After treatment, FISH demonstrated rearrangements of PAX3 and MAML3 genes, leading to a revised diagnosis of BSNS, which typically does not require chemotherapy due to its non-metastatic behavior. Eleven years after treatment, the patient remains free of recurrence. Understanding BSNS is essential to avoid excessive intervention, and confirmation of PAX3 rearrangement by FISH or equivalent molecular testing is crucial for accurate diagnosis.<\/jats:p>","DOI":"10.3390\/diagnostics16020266","type":"journal-article","created":{"date-parts":[[2026,1,14]],"date-time":"2026-01-14T11:01:14Z","timestamp":1768388474000},"page":"266","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["A Long-Term Disease-Free Case of Biphenotypic Sinonasal Sarcoma with Intracranial and Intraorbital Extension Initially Misdiagnosed as Synovial Sarcoma"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2180-8431","authenticated-orcid":false,"given":"Hiroyuki","family":"Morishita","sequence":"first","affiliation":[{"name":"Department of Otorhinolaryngology-Head and Neck Surgery, Mie University Graduate School of Medicine, Tsu 514-8507, Mie, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7133-1785","authenticated-orcid":false,"given":"Masayoshi","family":"Kobayashi","sequence":"additional","affiliation":[{"name":"Department of Otorhinolaryngology-Head and Neck Surgery, Mie University Graduate School of Medicine, Tsu 514-8507, Mie, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Masako","family":"Kitano","sequence":"additional","affiliation":[{"name":"Department of Otorhinolaryngology-Head and Neck Surgery, Mie University Graduate School of Medicine, Tsu 514-8507, Mie, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8981-5817","authenticated-orcid":false,"given":"Kazuki","family":"Kanayama","sequence":"additional","affiliation":[{"name":"Department of Oncologic Pathology, Mie University Graduate School of Medicine, Tsu 514-8507, Mie, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7321-1533","authenticated-orcid":false,"given":"Hiroshi","family":"Imai","sequence":"additional","affiliation":[{"name":"Pathology Division, Mie University Graduate School of Medicine, Tsu 514-8507, Mie, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"666","DOI":"10.1038\/ng.2989","article-title":"Recurrent PAX3-MAML3 fusion in biphenotypic sinonasal sarcoma","volume":"46","author":"Wang","year":"2014","journal-title":"Nat. Genet."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"517","DOI":"10.1097\/PAS.0b013e3182426886","article-title":"Low-grade sinonasal sarcoma with neural and myogenic features: A clinicopathologic analysis of 28 cases","volume":"36","author":"Lewis","year":"2012","journal-title":"Am. J. Surg. Pathol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"930","DOI":"10.1111\/his.13045","article-title":"Fusion gene profile of biphenotypic sinonasal sarcoma: An analysis of 44 cases","volume":"69","author":"Fritchie","year":"2016","journal-title":"Histopathology"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"6","DOI":"10.1016\/j.anndiagpath.2017.11.005","article-title":"Biphenotypic sinonasal sarcoma: A series of six cases with evaluation of role of \u03b2-catenin immunohistochemistry in differential diagnosis","volume":"33","author":"Kakkar","year":"2018","journal-title":"Ann. Diagn. 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Pathol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2087","DOI":"10.1200\/JCO.2000.18.10.2087","article-title":"Synovial sarcoma: A multivariate analysis of prognostic factors in 112 patients with primary localized tumors of the extremity","volume":"18","author":"Lewis","year":"2000","journal-title":"J. Clin. Oncol."}],"container-title":["Diagnostics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/2\/266\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,1,16]],"date-time":"2026-01-16T05:54:49Z","timestamp":1768542889000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/2\/266"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,14]]},"references-count":15,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2026,1]]}},"alternative-id":["diagnostics16020266"],"URL":"https:\/\/doi.org\/10.3390\/diagnostics16020266","relation":{},"ISSN":["2075-4418"],"issn-type":[{"value":"2075-4418","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1,14]]}}}