{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,30]],"date-time":"2026-06-30T01:47:25Z","timestamp":1782784045942,"version":"3.54.5"},"reference-count":28,"publisher":"Journal of Neurosurgery Publishing Group (JNSPG)","issue":"5","license":[{"start":{"date-parts":[[2025,2,3]],"date-time":"2025-02-03T00:00:00Z","timestamp":1738540800000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J Cosmet Laser Ther"],"published-print":{"date-parts":[[2025,2,3]]},"abstract":"<jats:sec>\n                    <jats:title>BACKGROUND<\/jats:title>\n                    <jats:p>Malignant transformation of epidermoid cysts (ECs) into squamous cell carcinoma (SCC) is extremely rare, with associated leptomeningeal carcinomatosis being much less likely. Malignant transformation of ECs has a poor prognosis with a median overall survival of 10 months following transformation.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>OBSERVATIONS<\/jats:title>\n                    <jats:p>A 59-year-old male with a history of a subtotally resected posterior fossa EC presented with worsening symptoms 14 years following the initial subtotal resection. Imaging showed obstructive hydrocephalus and extensive leptomeningeal carcinomatosis. Laboratory workup confirmed malignant transformation to SCC.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>LESSONS<\/jats:title>\n                    <jats:p>Nonmalignant recurrence of benign ECs is relatively common, often due to the complexity of complete resection and adherence to adjacent neurovascular structures. On the other hand, malignant degeneration of an EC is extremely rare. Any rapid change in symptoms, failure to recover following surgery, and new areas of irregular thickening and enhancement on imaging should prompt further evaluation for this process.<\/jats:p>\n                    <jats:p>\n                      <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" ext-link-type=\"uri\" xlink:href=\"https:\/\/thejns.org\/doi\/10.3171\/CASE24738\">https:\/\/thejns.org\/doi\/10.3171\/CASE24738<\/jats:ext-link>\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.3171\/case24738","type":"journal-article","created":{"date-parts":[[2025,2,3]],"date-time":"2025-02-03T01:47:33Z","timestamp":1738547253000},"source":"Crossref","is-referenced-by-count":4,"title":["Intracranial epidermoid cyst with malignant degeneration and leptomeningeal carcinomatosis: illustrative case"],"prefix":"10.3171","volume":"9","author":[{"given":"Hussein","family":"Alsadi","sequence":"first","affiliation":[{"name":"Department of Radiology, University of Kansas Medical Center, Kansas City, Kansas"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kelly","family":"Dahlstrom","sequence":"additional","affiliation":[{"name":"Department of Radiology, University of Kansas Medical Center, Kansas City, Kansas"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kyle","family":"Summers","sequence":"additional","affiliation":[{"name":"Department of Radiology, University of Kansas Medical Center, Kansas City, Kansas"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paul J.","family":"Camarata","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University of Kansas Medical Center, Kansas City, Kansas"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kyle","family":"Werth","sequence":"additional","affiliation":[{"name":"Department of Radiology, University of Kansas Medical Center, Kansas City, Kansas"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1754","reference":[{"issue":"9","key":"bib1","series-title":"J Clin Neurosci","first-page":"1158","article-title":"Clinical characteristics and diagnostic imaging of epidermoid tumors","volume":"18","author":"Nagasawa","year":"2011","unstructured":"Nagasawa DYew ASafaee MClinical characteristics and diagnostic imaging of epidermoid tumors. J Clin Neurosci. 2011;18(9):1158-1162."},{"issue":"5","key":"bib2","series-title":"Ann Neurol","first-page":"367","article-title":"Growth rates of epidermoid tumors","volume":"2","author":"Alvord","year":"1977","unstructured":"Alvord ECJr.Growth rates of epidermoid tumors. Ann Neurol. 1977;2(5):367-370."},{"issue":"2","key":"bib3","series-title":"J Neurooncol","first-page":"187","article-title":"Malignant transformation of intra-cranial epithelial cysts: systematic article review","volume":"74","author":"Hamlat","year":"2005","unstructured":"Hamlat AHua ZFSaikali SMalignant transformation of intra-cranial epithelial cysts: systematic article review. J Neurooncol. 2005;74(2):187-194."},{"key":"bib4","series-title":"World Neurosurg","first-page":"692.e9","article-title":"Primary intracranial epidermoid carcinoma with diffuse leptomeningeal carcinomatosis: report of two cases","volume":"88","author":"Raheja","year":"2016","unstructured":"Raheja AEli IMBowers CAPalmer CACouldwell WT.Primary intracranial epidermoid carcinoma with diffuse leptomeningeal carcinomatosis: report of two cases. World Neurosurg. 2016;88:692.e9-692.e16."},{"issue":"3","key":"bib5","series-title":"Neurol Med Chir (Tokyo)","first-page":"236","article-title":"Malignant transformation 20 years after partial removal of intracranial epidermoid cyst\u2014case report","volume":"50","author":"Nakao","year":"2010","unstructured":"Nakao YNonaka SYamamoto TMalignant transformation 20 years after partial removal of intracranial epidermoid cyst\u2014case report. Neurol Med Chir (Tokyo). 2010;50(3):236-239."},{"issue":"4","key":"bib6","series-title":"Neurol Med Chir (Tokyo)","first-page":"349","article-title":"Malignant transformation of an intracranial large epidermoid cyst with leptomeningeal carcinomatosis: case report","volume":"50","author":"Kano","year":"2010","unstructured":"Kano TIkota HKobayashi SIwasa SKurosaki SWada H.Malignant transformation of an intracranial large epidermoid cyst with leptomeningeal carcinomatosis: case report. Neurol Med Chir (Tokyo). 2010;50(4):349-353."},{"key":"bib7","series-title":"World Neurosurg","first-page":"e52","article-title":"Malignant transformation of an intracranial epidermoid cyst 25 years after initial surgery: a case report and systematic review","volume":"177","author":"Eatz","year":"2023","unstructured":"Eatz TAElarjani TChen SHMalignant transformation of an intracranial epidermoid cyst 25 years after initial surgery: a case report and systematic review. World Neurosurg. 2023;177:e52-e65."},{"issue":"2","key":"bib8","series-title":"Eur J Radiol","first-page":"214","article-title":"Intracranial epidermoid cysts: diffusion-weighted, FLAIR and conventional MR findings","volume":"54","author":"Hakyemez","year":"2005","unstructured":"Hakyemez BAksoy UYildiz HErgin N.Intracranial epidermoid cysts: diffusion-weighted, FLAIR and conventional MR findings. Eur J Radiol. 2005;54(2):214-220."},{"issue":"6","key":"bib9","series-title":"J Neurosurg","first-page":"1592","article-title":"Long-term surgical outcomes of intracranial epidermoid tumors: impact of extent of resection on recurrence and functional outcomes in 63 patients","volume":"136","author":"Hasegawa","year":"2022","unstructured":"Hasegawa HVakharia KCarlstrom LPLong-term surgical outcomes of intracranial epidermoid tumors: impact of extent of resection on recurrence and functional outcomes in 63 patients. J Neurosurg. 2022;136(6):1592-1600."},{"issue":"1","key":"bib10","series-title":"J Neurooncol","first-page":"89","article-title":"Radiotherapy for recurrent intracranial epidermoid cysts without malignant transformation: a single-institution case series","volume":"144","author":"Morshed","year":"2019","unstructured":"Morshed RAWu SYSneed PKMcDermott MW.Radiotherapy for recurrent intracranial epidermoid cysts without malignant transformation: a single-institution case series. J Neurooncol. 2019;144(1):89-96."},{"key":"bib11","series-title":"World Neurosurg","first-page":"e1","article-title":"Treatment and survival outcomes of primary intracranial squamous cell carcinoma","volume":"125","author":"Kwon","year":"2019","unstructured":"Kwon SMKim JHKim YHHong SHKim CJ.Treatment and survival outcomes of primary intracranial squamous cell carcinoma. World Neurosurg. 2019;125:e1-e9."},{"issue":"6","key":"bib12","series-title":"J Neurosurg","first-page":"824","article-title":"Primary intracranial squamous cell carcinoma of the right cerebellopontine angle","volume":"54","author":"Garcia","year":"1981","unstructured":"Garcia CAMcGarry PARodriguez F.Primary intracranial squamous cell carcinoma of the right cerebellopontine angle. J Neurosurg. 1981;54(6):824-828."},{"issue":"963","key":"bib13","series-title":"Br J Radiol","first-page":"e97","article-title":"CT and MR imaging features of intracerebral epidermoid\u2014a rare lesion","volume":"81","author":"Aribandi","year":"2008","unstructured":"Aribandi MWilson NJ.CT and MR imaging features of intracerebral epidermoid\u2014a rare lesion. 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Neurol Med Chir (Tokyo). 2010;50(3):236-239."},{"issue":"4","key":"bib6","series-title":"Neurol Med Chir (Tokyo)","first-page":"349","article-title":"Malignant transformation of an intracranial large epidermoid cyst with leptomeningeal carcinomatosis: case report","volume":"50","author":"Kano","year":"2010","unstructured":"Kano TIkota HKobayashi SIwasa SKurosaki SWada H.Malignant transformation of an intracranial large epidermoid cyst with leptomeningeal carcinomatosis: case report. Neurol Med Chir (Tokyo). 2010;50(4):349-353."},{"key":"bib7","series-title":"World Neurosurg","first-page":"e52","article-title":"Malignant transformation of an intracranial epidermoid cyst 25 years after initial surgery: a case report and systematic review","volume":"177","author":"Eatz","year":"2023","unstructured":"Eatz TAElarjani TChen SHMalignant transformation of an intracranial epidermoid cyst 25 years after initial surgery: a case report and systematic review. World Neurosurg. 2023;177:e52-e65."},{"issue":"2","key":"bib8","series-title":"Eur J Radiol","first-page":"214","article-title":"Intracranial epidermoid cysts: diffusion-weighted, FLAIR and conventional MR findings","volume":"54","author":"Hakyemez","year":"2005","unstructured":"Hakyemez BAksoy UYildiz HErgin N.Intracranial epidermoid cysts: diffusion-weighted, FLAIR and conventional MR findings. Eur J Radiol. 2005;54(2):214-220."},{"issue":"6","key":"bib9","series-title":"J Neurosurg","first-page":"1592","article-title":"Long-term surgical outcomes of intracranial epidermoid tumors: impact of extent of resection on recurrence and functional outcomes in 63 patients","volume":"136","author":"Hasegawa","year":"2022","unstructured":"Hasegawa HVakharia KCarlstrom LPLong-term surgical outcomes of intracranial epidermoid tumors: impact of extent of resection on recurrence and functional outcomes in 63 patients. 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