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

Deputy Editor-in-Chief: Debra Zynger, M.D.
Nirupama Singh, M.D., Ph.D.
Paul J. Biggs, M.D.

Topic Completed: 30 September 2019

Minor changes: 30 September 2019

Copyright: (c) 2002-2019,, Inc.

PubMed Search: Atypical teratoid/rhabdoid tumor (ATRT)

Nirupama Singh, M.D., Ph.D.
Paul J. Biggs, M.D.
Page views in 2019: 5,619
Page views in 2020 to date: 2,181
Cite this page: Singh, N., Biggs, P.J. Atypical teratoid / rhabdoid tumor (ATRT). website. Accessed May 27th, 2020.
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 atypical teratoid / rhabdoid tumor (ATRT)
  • Tumors with similar morphology but lacking this mutation are classified as CNS embryonal tumor with rhabdoid features
ICD coding
  • C71: malignant neoplasm of brain
  • Accounts for 1 - 2% of all pediatric brain tumors and is very rare in adults
  • Age typically < 3 years; rare 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
  • If > 3 years, headache and hemiplegia are reported
  • Cranial nerve palsy (mostly 6 and 7 nerve paresis) may also be present
  • WHO grade IV
Radiology description
  • Isodense to hyperintense on FLAIR images with restricted diffusion
Radiology images

Images hosted on other servers:

ATRT in a 9 month old

Heterogenous mass

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

Images hosted on PathOut server:

Images contributed by Nirupama Singh M.D., Ph.D.

Tumor cells with nucleus showing vesicular chromatin and prominent nucleoli

Eosinophilic globs

Mitotic figures

Images hosted on other servers:

Various images


Epithelioid areas




Spinal tumor

Cytology images

Images hosted on other servers:

Typical cytology

Positive stains
Negative stains
  • Germ cell markers and skeletal muscle differentiation markers (MyoD1, myogenin)
Molecular / cytogenetics description
Board review style question #1
Atypical rhabdoid / teratoid tumor is diagnosed by:

  1. NMYC amplication
  2. SMARCB1 and SMARCA4 genes
  3. TP53 mutation
  4. Tumor cells with high N/C ratios and frequent smudge artifacts on smears
Board review answer #1
B. SMARCB1 is the most common and SMARCA4 is more rare
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