Implications of tumor location on subtypes of medulloblastoma

Pediatr Blood Cancer. 2013 Sep;60(9):1408-10. doi: 10.1002/pbc.24511. Epub 2013 Mar 19.


Background: Medulloblastoma (MB) comprises of four molecular subtypes, Sonic hedgehog (SHH), Wingless (WNT), Groups 3 and 4. WNT-subtype MBs were found to arise from midline of the brainstem occupying the fourth ventricle while SHH-subtype occupied the cerebellar hemisphere in a small subset of patients.

Procedure: We tested this hypothesis in a large cohort of pediatric MBs comprising of all four molecular subtypes.

Results: We validated in the first comprehensive analysis of tumor location of 60 human MBs representative of the four molecular subtypes, that hemispheric tumors are significantly associated with SHH-subtype MBs while midline tumors with WNT-subtype, Group 3 and 4 MBs (P < 0.001). Nearly half of SHH-subtype MBs were midline.

Conclusions: Tumor location should not be generalized to MB subtypes. SHH-subtype MBs are not exclusively hemispheric and hemispheric MBs are not always SHH-activated. It is imperative to identify subtypes in conjunction with tumor location when exploring currently available targeted therapy.

Keywords: medulloblastoma; molecular subtypes; pediatric; tumor location.

Publication types

  • Clinical Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Cerebellar Neoplasms* / classification
  • Cerebellar Neoplasms* / diagnostic imaging
  • Cerebellar Neoplasms* / genetics
  • Child
  • Child, Preschool
  • Female
  • Hedgehog Proteins / genetics*
  • Humans
  • Infant
  • Magnetic Resonance Imaging*
  • Male
  • Medulloblastoma* / classification
  • Medulloblastoma* / diagnostic imaging
  • Medulloblastoma* / genetics
  • Radiography
  • Retrospective Studies


  • Hedgehog Proteins
  • SHH protein, human