Recurrent pseudoprogression in isocitrate dehydrogenase 1 mutant glioblastoma

J Clin Neurosci. 2018 Jul;53:255-258. doi: 10.1016/j.jocn.2018.04.056. Epub 2018 May 10.


In a subset of glioblastoma (GBM) patients, the differentiation between tumor progression and tumor pseudoprogression (PsP) is challenging. This case describes a male patient suffering from isocitrate dehydrogenase 1 (IDH1) mutant GBM who demonstrated an increasing contrast-enhancing (CE) lesion on a cranial magnetic resonance imaging (cMRI) scan 8 months after radiochemotherapy. In accordance with the response assessment in neuro-oncology (RANO) criteria, the cMRI lesion was classified as recurrent tumor, although 18F-fluoroethyl-L-tyrosine positron emission tomography (18F-FET-PET) did not indicate vital tumor tissue. The patient underwent re-surgery but histopathology only revealed reactive and necrotic tissue, consistent with PsP. Nine weeks after complete resection of the CE lesion, a new lesion emerged that later regressed in the follow-up cMRI scans, thereby retrospectively establishing the diagnosis of recurrent PsP.

Keywords: (18)F-FET-PET; Pseudoprogression; RANO; Recurrent pseudoprogression.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • Brain Neoplasms / diagnostic imaging
  • Brain Neoplasms / genetics*
  • Brain Neoplasms / pathology*
  • Chemoradiotherapy / methods
  • Disease Progression
  • Glioblastoma / diagnostic imaging
  • Glioblastoma / genetics*
  • Glioblastoma / pathology*
  • Humans
  • Isocitrate Dehydrogenase / genetics*
  • Male
  • Middle Aged
  • Neoplasm Recurrence, Local / diagnostic imaging
  • Positron-Emission Tomography / methods
  • Radiopharmaceuticals
  • Retrospective Studies
  • Tyrosine / analogs & derivatives


  • Radiopharmaceuticals
  • (18F)fluoroethyltyrosine
  • Tyrosine
  • Isocitrate Dehydrogenase
  • IDH1 protein, human