title: Multifocal glioblastoma multiforme in the posterior fossa mimicking cerebral metastases: case presentation and review of the current literature.
abstract: OBJECTIVE
  In general, glioblastomas multiforme (GBM) arise in the supratentorial region, but in less than 4% of cases they also occur in the posterior fossa, particularly in the cerebellum. Furthermore, a minority of malignant gliomas are multifocal. We report on an unusual case with infratentorial multifocal lesions, suspicious for metastases, which turned out to be a multifocal GBM of the posterior fossa.
  
  
  METHODS
  A 69-year-old woman presented with recurring episodes of vertigo, headache, and progressive weight loss. Three multifocal cerebellar and brainstem lesions highly suspicious for metastases were identified by magnetic resonance imaging (MRI). Workup for malignancy elsewhere in the body was negative.
  
  
  RESULTS
  The patient underwent craniotomy with successful resection of the tumor in the cerebellar vermis with an excellent outcome and uneventful postsurgical course. Histopathology of the tumor revealed features consistent with the diagnosis of GBM and ruled out metastatic lesions. Workup for molecular genetics characterized this tumor as a primary GBM. The patient initially responded to treatment with radiation therapy and temozolomide but died after 10 months with a tumor relapse.
  
  
  CONCLUSIONS
  We discuss the unusual aspects of multifocal primary GBMs in the posterior fossa. Although rare, they should be considered in the differential diagnosis of cerebellar tumors, which stresses the importance of a surgical treatment to establish a histological diagnosis because there are no reliable radiographic criteria for distinguishing multifocal infratentorial gliomas from multiple metastases and other tumor entities. The differentiation between a primary and secondary cerebellar GBM did not lead to any change of the treatment strategy in this case.
authors: Department of Neurosurgery, Friedrich-Schiller-University, Jena, Germany.
authors: Jan
authors: J
authors: Walter
authors: Department of Neuropathology, Charité-Universitätsmedizin, Berlin, Germany.
authors: Arend
authors: A
authors: Koch
authors: Department of Neurosurgery, Friedrich-Schiller-University, Jena, Germany.
authors: Christian
authors: C
authors: Herbold
authors: Department of Neuroradiology, Friedrich-Schiller-University, Jena, Germany.
authors: Sascha
authors: S
authors: Schiffler
authors: Department of Neurosurgery, Friedrich-Schiller-University, Jena, Germany.
authors: Rupert
authors: R
authors: Reichart
authors: Department of Neurosurgery, Friedrich-Schiller-University, Jena, Germany.
authors: Albrecht
authors: A
authors: Waschke
authors: Department of Neurosurgery, Friedrich-Schiller-University, Jena, Germany.
authors: Rolf
authors: R
authors: Kalff
mesh_terms: D000368:Aged; D001932:Brain Neoplasms / Q000473:pathology* / Q000556:secondary* / Q000628:therapy; D001933:Brain Stem / Q000473:pathology; D059248:Chemoradiotherapy; D003131:Combined Modality Therapy; D003388:Cranial Fossa, Posterior / Q000473:pathology / Q000601:surgery*; D003399:Craniotomy; D015254:DNA Modification Methylases / Q000235:genetics; D045643:DNA Repair Enzymes / Q000235:genetics; D003937:Diagnosis, Differential; D017809:Fatal Outcome; D005260:Female; D005909:Glioblastoma / Q000473:pathology / Q000601:surgery* / Q000628:therapy; D006801:Humans; D008279:Magnetic Resonance Imaging; D009364:Neoplasm Recurrence, Local; D019635:Neurosurgical Procedures; D016896:Treatment Outcome; D025521:Tumor Suppressor Proteins / Q000235:genetics
chemical_list: D025521:Tumor Suppressor Proteins; D015254:DNA Modification Methylases; C515491:MGMT protein, human; D045643:DNA Repair Enzymes