CNS tumor
Embryonal tumors
Atypical teratoid / rhabdoid tumor (ATRT)
Copyright: (c) 2002-2019, PathologyOutlines.com, Inc.
PubMed Search: Atypical teratoid/rhabdoid tumor (ATRT)
Embryonal tumors
Atypical teratoid / rhabdoid tumor (ATRT)
Deputy Editor-in-Chief: Debra Zynger, M.D.
Topic Completed: 30 September 2019
Minor changes: 30 September 2019
Copyright: (c) 2002-2019, PathologyOutlines.com, Inc.
PubMed Search: Atypical teratoid/rhabdoid tumor (ATRT)
Table of Contents
Definition / general | Essential features | ICD coding | Epidemiology | Sites | Clinical features | Grading | Radiology description | Radiology images | Prognostic factors | Case reports | Treatment | Microscopic (histologic) description | Microscopic (histologic) images | Cytology images | Positive stains | Negative stains | Molecular / cytogenetics description | Board review style question #1 | Board review answer #1Cite this page: Singh, N., Biggs, P.J. Atypical teratoid / rhabdoid tumor (ATRT). PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cnstumoratypicalteratoidrhabdoid.html. 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
Epidemiology
- 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
Sites
- 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
Grading
- 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
- 10 month old girl with rapidly progressive paraplegia (Clin Neuropathol 2006;25:81)
- 16 month old boy with progressive urinary retention (Spinal Cord Ser Cases 2017;3:16026)
- 7 year old boy with spinal atypical teratoid / rhabdoid tumor (Neuropathology 2007;27:139)
- Adolescent with an ATRT and simultaneous low grade glioneuronal tumor (J Pediatr Hematol Oncol 2017;39:e456)
- Adolescent with atypical teratoid rhabdoid tumor involving the nasal cavities and anterior skull base (Neuropathology 2016;36:283)
- 19 year old man with atypical teratoid / rhabdoid tumor of the pineal region (J Neurol Surg A Cent Eur Neurosurg 2017;78:92)
Treatment
- Surgery, high dose chemotherapy with radiation (Pediatr Blood Cancer 2017 Dec;64(12))
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
H&E
Epithelioid areas
Vimentin
EMA
GFAP
Spinal tumor
Cytology images
Images hosted on other servers:
Typical cytology
Positive stains
- Rhabdoid cells are positive for EMA, SMA and vimentin
- Cytokeratins, GFAP, NFP and synaptophysin staining are also observed
Molecular / cytogenetics description
- Loss of SMARCB1 expression at the protein level is seen in most ATRT tumors (Cancer Biol Ther 2009;8:412, Pediatr Dev Pathol 2018;21:6, Neuropathology 2018;38:305)
Board review style question #1
Atypical rhabdoid / teratoid tumor is diagnosed by:
- NMYC amplication
- SMARCB1 and SMARCA4 genes
- TP53 mutation
- 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
