Immunohistochemical analysis of hSNF5/INI1 in pediatric CNS neoplasms

Am J Surg Pathol. 2004 May;28(5):644-50. doi: 10.1097/00000478-200405000-00013.


Atypical teratoid/rhabdoid tumor (AT/RT) may be misdiagnosed as primitive neuroectodermal tumor/medulloblastoma (PNET) and occasionally as other tumors. Molecular genetic analysis of AT/RT demonstrates deletion and mutation of the hSNF5/INI1 gene in most cases, with decreased or absent expression at the RNA or protein level. Immunohistochemistry with an antibody to INI1 was performed to determine whether this would be a sensitive and specific means of assessing INI1 loss in pediatric brain tumors. Fifty-three tumors consisting of 20 AT/RTs, 10 PNETs, and 23 other central nervous system tumors were examined. No nuclear staining was found in all 20 AT/RTs. Most other central nervous system tumors demonstrated nuclear staining. Eight cases in which classification as AT/RT or PNET was difficult were also examined. Seven cases had no chromosome 22 deletion or INI1 mutation; INI1 antibody showed nuclear staining in these cases. One case was a recurrent tumor with features consistent with an AT/RT. INI1 immunostaining was negative in this case, and a mutation in INI1 was subsequently identified. Immunohistochemical staining with an INI1 antibody correlates with molecular findings in AT/RT and may be useful in confirming the histologic diagnosis. INI1 immunostaining may have particular utility in the analysis of tumors with indeterminate histologic features or atypical immunophenotypic profiles.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Biomarkers, Tumor / analysis
  • Brain Neoplasms / chemistry
  • Brain Neoplasms / genetics*
  • Brain Neoplasms / pathology
  • Cell Nucleus / chemistry
  • Cell Nucleus / genetics
  • Cell Nucleus / pathology
  • Child
  • Child, Preschool
  • Chromosomal Proteins, Non-Histone
  • Chromosome Deletion
  • Chromosomes, Human, Pair 22
  • DNA, Neoplasm / analysis
  • DNA-Binding Proteins / analysis
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / immunology
  • Female
  • Humans
  • Immunoenzyme Techniques
  • In Situ Hybridization, Fluorescence
  • Infant
  • Male
  • Mutation
  • Neuroectodermal Tumors, Primitive / chemistry
  • Neuroectodermal Tumors, Primitive / genetics*
  • Neuroectodermal Tumors, Primitive / pathology
  • Rhabdoid Tumor / chemistry
  • Rhabdoid Tumor / genetics*
  • Rhabdoid Tumor / pathology
  • SMARCB1 Protein
  • Teratoma / chemistry
  • Teratoma / genetics*
  • Teratoma / pathology
  • Transcription Factors


  • Biomarkers, Tumor
  • Chromosomal Proteins, Non-Histone
  • DNA, Neoplasm
  • DNA-Binding Proteins
  • SMARCB1 Protein
  • SMARCB1 protein, human
  • Transcription Factors