CNS tumor
Embryonal tumors
Atypical teratoid / rhabdoid tumor (ATRT)

Author: Nirupama Singh M.D., Ph.D.

Revised: 19 January 2018, last major update January 2018

Copyright: (c) 2002-2018,, Inc.

PubMed Search: Atypical teratoid/rhabdoid tumor (ATRT)

Cite this page: Singh, N. Atypical teratoid / rhabdoid tumor (ATRT). website. Accessed January 20th, 2018.
Definition / general
  • Malignant CNS embryonal tumor composed of poorly differentiated cells including rhabdoid cells
  • Occurs in young children; diagnosis is based on demonstrating loss of INI1
  • Tumors with similar morphology but lacking characteristic molecular findings are classified as CNS embryonal tumors with rhabdoid features
Essential features
  • Loss of SMARCB1 or SMARCA4 genes is required for the diagnosis of ATRT
  • Tumors with similar morphology but lacking this mutation are classified as CNS embryonal tumor with rhabdoid features
ICD-10 coding
  • C71: malignant neoplasm of brain
  • Accounts for 1 - 2% of all pediatric brain tumors and is very rare in adults
  • Presents in < 3 years and rarely in children aged > 6 years
  • Can occur in cerebral hemispheres, cerebellum or rarely in the spinal cord
  • Cerebral hemispheres
  • Cerebellar hemispheres
  • Cerebellopontine angle
  • Brain stem
  • In adults, the most common site is cerebral hemispheres
Clinical features
  • Depends on age and location
  • In infants, lethargy, vomiting and failure to thrive are common symptoms
  • Headache and hemiplegia are reported in > 3 years
  • Cranial nerve palsy (mostly 6 and 7 nerve paresis) may also be present
  • WHO grade IV
Radiology description
  • Isodense to hyperintense on FLAIR images and show restricted diffusion
Radiology images

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Heterogenous mass

Prognostic factors
  • Poor with 5 year progression free and overall survival rate of 60% even for the favourable group
Case reports
Microscopic (histologic) description
  • Diagnostic feature on histology is the presence of cells with rhabdoid features, which include:
    • Eccentrically located nuclei containing vesicular chromatin
    • Prominent eosinophilic nucleoli
    • Abundant cytoplasm with eosinophilic inclusions
    • Well defined cell borders
  • Cytoplasm is granular
  • Primitive neuroectodermal component is most common
  • Mesenchymal and epithelial features are less common
Microscopic (histologic) images

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Hint of rhabdoid features

Various images


Epithelioid areas




Spinal tumor

Cytology images

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Typical cytology

Positive stains
Negative stains
  • Germ cell markers and skeletal muscle differentiation markers (MyoD1, myogenin)
Molecular / cytogenetics description