{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,8,29]],"date-time":"2025-08-29T00:03:29Z","timestamp":1756425809741,"version":"3.44.0"},"reference-count":16,"publisher":"BMJ","issue":"9","license":[{"start":{"date-parts":[[2023,9,20]],"date-time":"2023-09-20T00:00:00Z","timestamp":1695168000000},"content-version":"unspecified","delay-in-days":19,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2023,8,14]]},"published-print":{"date-parts":[[2023,9]]},"abstract":"<jats:p>We report about a case of a woman in her 50s with a chondrosarcoma of the petrous apex. She has a strabism due to a right-sided amblyopia since childhood and noticed a slowly progressive squint angle in the last months. Her general practitioner (GP) referred her to an ophthalmologist who diagnosed a left abducens paresis and initiated an MRI demonstrating a mass in the left petrous apex. A transnasal endoscopic transsphenoidal biopsy revealed a grade I chondrosarcoma. The patient underwent an endoscopic transsphenoidal anterior petrosectomy approach with complete removal of the tumour. After surgery the squint angle gradually improved to previous levels, so that the patient was able to resume her work. This report demonstrates that even slight changes of a squint angle without diplopia, in this case because of pre-existing amblyopia, could be a hallmark of an intracranial process.<\/jats:p>","DOI":"10.1136\/bcr-2023-256273","type":"journal-article","created":{"date-parts":[[2023,9,20]],"date-time":"2023-09-20T13:06:13Z","timestamp":1695215173000},"page":"e256273","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":1,"title":["Chondrosarcoma of the petrous apex with nerve abducens involvement in a woman with pre-existing contralateral amblyopia"],"prefix":"10.1136","volume":"16","author":[{"given":"Letizia","family":"Meier","sequence":"first","affiliation":[{"name":"Klinik f\u00fcr Hals-, Nasen-, Ohren- und Gesichtschirurgie, Luzerner Kantonsspital, Luzern, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gunesh","family":"Rajan","sequence":"additional","affiliation":[{"name":"Klinik f\u00fcr Hals-, Nasen-, Ohren- und Gesichtschirurgie, Luzerner Kantonsspital, Luzern, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2023,9,20]]},"reference":[{"key":"2025082801310646000_16.9.e256273.1","doi-asserted-by":"publisher","DOI":"10.1016\/S0030-6665(05)70363-7"},{"key":"2025082801310646000_16.9.e256273.2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jocn.2009.05.003"},{"key":"2025082801310646000_16.9.e256273.3","unstructured":"Who Classification Of Tumours Editorial Board . Soft tissue and bone tumours. Lyon International Agency For Research On Cancer, 2020."},{"key":"2025082801310646000_16.9.e256273.4","doi-asserted-by":"crossref","DOI":"10.3390\/cancers13235960","article-title":"Primary skull base chondrosarcomas: a systematic review","volume":"13","author":"Palmisciano","year":"2021","journal-title":"Cancers (Basel)"},{"key":"2025082801310646000_16.9.e256273.5","article-title":"Chondrosarcoma of the skull base: a case study and literature review","volume":"12","author":"Konovalov","year":"2020","journal-title":"Cureus"},{"key":"2025082801310646000_16.9.e256273.6","doi-asserted-by":"crossref","first-page":"940","DOI":"10.1097\/MAO.0000000000001037","article-title":"Petroclival chondrosarcoma","volume":"37","author":"Carlson","year":"2016","journal-title":"Otology & Neurotology"},{"key":"2025082801310646000_16.9.e256273.7","doi-asserted-by":"crossref","first-page":"501","DOI":"10.1016\/j.otc.2015.02.009","article-title":"Chordoma and chondrosarcoma","volume":"48","author":"Van Gompel","year":"2015","journal-title":"Otolaryngol Clin North Am"},{"key":"2025082801310646000_16.9.e256273.8","doi-asserted-by":"crossref","first-page":"581","DOI":"10.1007\/s11060-022-04097-2","article-title":"Revisitation of imaging features of skull base chondrosarcoma in comparison to chordoma","volume":"159","author":"Hasegawa","year":"2022","journal-title":"J Neurooncol"},{"key":"2025082801310646000_16.9.e256273.9","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1093\/neuros\/nyab209","article-title":"Skull base tumors: neuropathology and clinical implications","volume":"90","author":"Bi","year":"2022","journal-title":"Neurosurgery"},{"key":"2025082801310646000_16.9.e256273.10","doi-asserted-by":"crossref","first-page":"212","DOI":"10.4103\/JOC.JOC_96_20","article-title":"Low-grade chondrosarcoma of petrous apex diagnosed by intraoperative crush smear cytology","volume":"37","author":"Khonglah","year":"2020","journal-title":"J Cytol"},{"key":"2025082801310646000_16.9.e256273.11","doi-asserted-by":"crossref","unstructured":"Lawrence JD , Marsh R , Turner MT . Contralateral transmaxillary approach for resection of chondrosarcoma of the petrous apex: case report. Special Virtual Symposium of the North American Skull Base Society; 2021 doi:10.1055\/s-0041-1725462","DOI":"10.1055\/s-0041-1725462"},{"key":"2025082801310646000_16.9.e256273.12","doi-asserted-by":"crossref","first-page":"e83","DOI":"10.1055\/s-0038-1673627","article-title":"Chondrosarcoma in the petrous apex: case report and review","volume":"79","author":"Banaz","year":"2018","journal-title":"J Neurol Surg Rep"},{"key":"2025082801310646000_16.9.e256273.13","doi-asserted-by":"crossref","first-page":"1609","DOI":"10.3171\/2018.1.JNS171972","article-title":"Endoscope-assisted contralateral Transmaxillary approach to the Clivus and the Hypoglossal canal: technical case report","volume":"130","author":"Pamias-Portalatin","year":"2019","journal-title":"J Neurosurg"},{"key":"2025082801310646000_16.9.e256273.14","doi-asserted-by":"crossref","first-page":"811","DOI":"10.1016\/j.wneu.2016.12.086","article-title":"Spontaneous Intraventricular hemorrhage: a rare presentation of a skull base mesenchymal chondrosarcoma","volume":"99","author":"Laghari","year":"2017","journal-title":"World Neurosurgery"},{"key":"2025082801310646000_16.9.e256273.15","doi-asserted-by":"publisher","DOI":"10.1007\/s11060-021-03764-0"},{"key":"2025082801310646000_16.9.e256273.16","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0208786","article-title":"Surgery and protontherapy in grade I and II skull base chondrosarcoma: a comparative retrospective study","volume":"13","author":"Simon","year":"2018","journal-title":"PLoS One"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2023-256273","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,8,28]],"date-time":"2025-08-28T08:31:14Z","timestamp":1756369874000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2023-256273"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,9]]},"references-count":16,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2023,9,20]]},"published-print":{"date-parts":[[2023,9]]}},"alternative-id":["10.1136\/bcr-2023-256273"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2023-256273","relation":{},"ISSN":["1757-790X"],"issn-type":[{"type":"electronic","value":"1757-790X"}],"subject":[],"published":{"date-parts":[[2023,9]]}}}