Chordoma dedifferentiation after proton beam therapy: a case report and review of the literature

Joseph Frankl, Cassi Grotepas, Baldassarre Stea, Gerald M Lemole, Alexander G Chiu, Rihan Khan

Research output: Contribution to journalArticle

4 Scopus citations


Background: Chordoma is a rare invasive bone tumor that may occur anywhere along the neuraxis. A total of three primary histological varieties have been identified: conventional, chondroid, and dedifferentiated. Case presentation: We report a case of an 8-year-old white girl who presented with conventional chordoma, was treated with surgical resection and mixed proton and photon beam therapy, and had a recurrence in the resection cavity 2.5 years later with dedifferentiated morphology. The recurrent tumor did not express brachyury, a recently identified protein specific to tissue of notochordal origin. Conclusions: The short time period between radiation therapy and dedifferentiation, low dose of photons, and rarity of dedifferentiated skull base chordomas in pediatric patients should alert clinicians to the possibility of chordoma dedifferentiation after proton beam therapy.

Original languageEnglish (US)
Pages (from-to)1-6
Number of pages6
JournalJournal of Medical Case Reports
Issue number1
Publication statusPublished - Oct 12 2016



  • Case report
  • Chordoma
  • Dedifferentiation
  • Oncology
  • Pediatric tumors
  • Proton beam therapy

ASJC Scopus subject areas

  • Medicine(all)

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