Atypical Teratoid-Rhabdoid Tumor
BASIC DESCRIPTION
- Aggressive, infiltrative pediatric rhabdoid tumor with highly variable appearance and histology
PATHOLOGY
- WHO grade IV
- Involves mesenchymal, neuronal, glial, and epithelial cell lines (“teratoid”)
- ±Rhabdoid cells, primitive neuroectodermal cells
- Mutations of SMARCB1/hSNF5 and loss of INI1 protein is diagnostic of atypical teratoid-rhabdoid tumor (AT/RT)
- Familial mutations in rhabdoid tumor predisposition syndrome (RTPS)
CLINICAL FEATURES
- Most commonly afflicts children <3 years old and usually in the posterior fossa; tumors in adults are often in an atypical location
- No gender predilection
- Common presenting signs/symptoms related to increased intracranial pressure/hydrocephalus
- Vomiting, altered mental status, macrocephaly
- Treatment: surgical resection ± adjuvant chemoradiation
- Often unresectable
- Prognosis: overall 5-year survival, <30%
- Survival with leptomeningeal spread, 16 months
- Survival without leptomeningeal spread, 149 months
IMAGING FEATURES
- General
- Highly variable, nonspecific morphology and imaging characteristics
- Supratentorial or infratentorial
- More than half arise within the posterior fossa
- Variable size; often large at time of diagnosis
- Mixed solid-cystic mass
- ±Calcification, hemorrhage, and necrosis
- ±Obstructive hydrocephalus
- Leptomeningeal/cerebrospinal fluid (CSF) dissemination common (>30%)
- CT
- Hyperdense mass
- Hyperdense calcification and hemorrhage or hypodense cysts may be seen
- Avid, heterogeneous enhancement on contrast-enhanced CT
- MRI
- T1-weighted imaging (T1WI), heterogeneous signal due to cystic or hemorrhagic components
- T2-weighted imaging (T2WI), heterogeneous signal due to cystic or hemorrhagic components
- Fluid-attenuated inversion recovery (FLAIR) imaging, heterogeneous, hyperintense periventricular signal due to hydrocephalus/interstitial edema, little peritumoral edema
- Gradient recalled echo T2*-weighted imaging (T2*GRE), hypointense signal due to calcification and hemorrhage
- T1WI+C imaging, majority show heterogeneous enhancement; may see enhancing CSF dissemination along the brain, cranial nerves, spinal nerves, or spinal cord
- Diffusion-weighted imaging (DWI), demonstrates diffusion restriction in hypercellular regions of tumor
- MR spectroscopy, elevated Cho, decreased NAA, ±lactate/lipid peaks
IMAGING RECOMMENDATIONS
- MRI without and with intravenous contrast including both brain and spine due to risk of CSF dissemination
For more information, please see the corresponding chapter in Radiopaedia.
Contributor: Rachel Seltman, MD
References
Bruggers CS, Moore K. Magnetic resonance imaging spectroscopy in pediatric atypical teratoid rhabdoid tumors of the brain. J Pediatr Hematol Oncol 2014;36:e341–e345. doi.org/10.1097/MPH.0000000000000041.
Koral K, Gargan L, Bowers DC, et al. Imaging characteristics of atypical teratoid-rhabdoid tumor in children compared with medulloblastoma. AJR Am J Roentgenol 2008;190:809–814. doi.org/10.2214/AJR.07.3069.
Margol AS, Judkins AR. Pathology and diagnosis of SMARCB1-deficient tumors. Cancer Genet 2014;207:358–364. doi.org/10.1016/j.cancergen.2014.07.004.
Meyers SP, Khademian ZP, Biegel JA, et al. Primary intracranial atypical teratoid/rhabdoid tumors of infancy and childhood: MRI features and patient outcomes. AJNR Am J Neuroradiol 2006;27:962–971.
Osborn AG, Salzman KL, Jhaveri MD. Diagnostic Imaging (3rd ed). Elsevier, Philadelphia, PA; 2016.
Parmar H, Hawkins C, Bouffet E, et al. Imaging findings in primary intracranial atypical teratoid/rhabdoid tumors. Pediatr Radiol 2006;36:126–132. doi.org/10.1007/s00247-005-0037-6.
Warmuth-Metz M, Bison B, Dannemann-Stern E, et al. CT and MR imaging in atypical teratoid/rhabdoid tumors of the central nervous system. Neuroradiology 2008;50:447–452. doi.org/10.1007/s00234-008-0369-7.
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