{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T15:33:50Z","timestamp":1777563230012,"version":"3.51.4"},"reference-count":8,"publisher":"SAGE Publications","license":[{"start":{"date-parts":[[2025,6,25]],"date-time":"2025-06-25T00:00:00Z","timestamp":1750809600000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"},{"start":{"date-parts":[[2025,6,25]],"date-time":"2025-06-25T00:00:00Z","timestamp":1750809600000},"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":["Ear Nose Throat J"],"abstract":"<jats:p>Isolated Horner syndrome (HS) in young children warrants thorough investigation for occult malignancy, despite its rarity as a presenting sign. This report details a unique case of a 30 month-old male presenting with sudden-onset, isolated left HS as the sole manifestation of rhabdomyosarcoma (RMS) in parapharyngeal space. Contrast-enhanced magnetic resonance imaging (MRI) revealed a 2.5 \u00d7 3.5 \u00d7 5 cm lesion within the left poststyloid parapharyngeal space, displacing the carotid artery anteriorly, and the internal jugular vein posteriorly. Gross total resection via a transcervical approach was performed; intraoperatively, the tumor involved the cervical sympathetic trunk, necessitating its sacrifice, resulting in persistent postoperative HS. Histopathological and immunohistochemical analysis (positive CK, PLAP, CD99) confirmed a diagnosis of embryonal RMS. The child received adjuvant chemoradiotherapy. One-year follow-up with positron emission tomography - computed tomography (PET-CT) showed no evidence of recurrence. This case underscores several critical points: (1) Isolated HS in young children necessitates urgent neuroimaging to exclude malignancy, even in the absence of palpable masses or neurological deficits; (2) The parapharyngeal space, though an exceptionally rare primary site for RMS (constituting a minor subset of head and neck cases), carries significant implications due to its proximity to the sympathetic chain, readily causing HS via mass effect; (3) MRI is pivotal for diagnosis and surgical planning in this anatomically complex region; (4) Multimodal therapy is essential for local control in embryonal RMS; (5) Sacrifice of the sympathetic trunk during resection likely leads to permanent HS, a factor for preoperative counseling. Vigilant long-term follow-up remains crucial.<\/jats:p>","DOI":"10.1177\/01455613251352732","type":"journal-article","created":{"date-parts":[[2025,6,26]],"date-time":"2025-06-26T00:44:15Z","timestamp":1750898655000},"update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":1,"title":["Isolated Horner Syndrome as the Sole Presentation of Pediatric Parapharyngeal Rhabdomyosarcoma"],"prefix":"10.1177","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-9008-5158","authenticated-orcid":false,"given":"Molham","family":"Alahmad","sequence":"first","affiliation":[{"name":"Department of Otorhinolaryngology, Al Mouwasat University Hospital, Damascus University, Damascus, Syria"},{"name":"Faculty of Medicine, Damascus University, Damascus, Syria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6479-8547","authenticated-orcid":false,"given":"Ahmad","family":"Alkheder","sequence":"additional","affiliation":[{"name":"Department of Otorhinolaryngology, Al Mouwasat University Hospital, Damascus University, Damascus, Syria"},{"name":"Faculty of Medicine, Damascus University, Damascus, Syria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Arige","family":"Alassaf","sequence":"additional","affiliation":[{"name":"Department of Otorhinolaryngology, Al Mouwasat University Hospital, Damascus University, Damascus, Syria"},{"name":"Faculty of Medicine, Damascus University, Damascus, Syria"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"179","published-online":{"date-parts":[[2025,6,25]]},"reference":[{"key":"e_1_3_2_2_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00432-017-2544-x"},{"key":"e_1_3_2_3_2","doi-asserted-by":"publisher","DOI":"10.14639\/0392-100X-1450"},{"key":"e_1_3_2_4_2","doi-asserted-by":"publisher","DOI":"10.1016\/0278-2391(89)90349-2"},{"key":"e_1_3_2_5_2","doi-asserted-by":"publisher","DOI":"10.1308\/rcsbull.2019.8"},{"key":"e_1_3_2_6_2","doi-asserted-by":"publisher","DOI":"10.1177\/2329048X231219205"},{"key":"e_1_3_2_7_2","doi-asserted-by":"publisher","DOI":"10.1177\/01455613241290177"},{"key":"e_1_3_2_8_2","doi-asserted-by":"publisher","DOI":"10.24953\/turkjped.2021.4600"},{"key":"e_1_3_2_9_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jaapos.2014.11.007"}],"container-title":["Ear, Nose &amp; Throat Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/01455613251352732","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/full-xml\/10.1177\/01455613251352732","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/01455613251352732","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T18:38:49Z","timestamp":1777401529000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/01455613251352732"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,25]]},"references-count":8,"alternative-id":["10.1177\/01455613251352732"],"URL":"https:\/\/doi.org\/10.1177\/01455613251352732","relation":{},"ISSN":["0145-5613","1942-7522"],"issn-type":[{"value":"0145-5613","type":"print"},{"value":"1942-7522","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,6,25]]},"article-number":"01455613251352732"}}