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Atypical Teratoid / Rhaboid Tumour (AT/RT)

Tumour Group:
Embryonal Tumours and Pediatric Brain Tumours
WHO Grade:
Grade IV
AT/RT's are rare, accounting for 1 to 2% of pediatric brain tumours. However, due to the number of cases in children under the age of three, AT/RT are estimated to account for at least 20% of the central nervous system (CNS) tumours in infants.
Typical Age Range:
These tumours typically occur in children age 3 and younger.

Tumour Characteristics

AT/RT is a very aggressive brain tumour seen in infants and young children. The tumour is characterized through a mutation of the tumour suppresor gene INI1. Genetic predisposition (germline mutation) can be found in up to 35% of patients. Therefore genetic testing for patients and parents is warranted.

About half of AT/RT’s are found in the cerebellum or brainstem. However, they may appear anywhere in the brain or spinal cord. An AT/RT can appear as a large, bulky mass.


Common symptoms include, but are not necessarily limited to:

  • Change in activity level
  • Increased head size (in infants)
  • Lack of coordination
  • Loss of balance
  • Morning headache or headache that goes away after vomitting
  • Nausea and vomitting
  • Trouble walking and regression of milestones
  • Unusual sleepiness

Treatment/Standard of Care

Currently, there are no standard-of-care treatment protocols for AT/RT. Treatment generally involves several approaches including surgery to remove the tumour, followed by chemotherapy and/or high-dose chemotherapy, and stem cell transplant. Frequently focal radiation is also considered as part of the treatment plan.


A prognosis is an estimate of the likely progress of a disease after a diagnosis, based on an average patient group. Since every person is different, please take time to talk with your health care team about how this information applies to you.

By clicking on 'expand', a statistic on the prognosis for Atypical Teratoid / Rhaboid Tumour (AT/RT) will be shown.