Pineoblastoma
BASIC DESCRIPTION
- Malignant, invasive pineal parenchymal tumor arising from embryonic pineocyte precursors (PNET)
PATHOLOGY
- WHO grade IV
- Invades adjacent structures, often including the cerebral aqueduct
- Cerebrospinal fluid (CSF) dissemination common
- Hypercellularity and increased mitoses are characteristic features
- Associated with germline DICER1 mutations (DICER1 syndrome) and RB1 (bilateral retinoblastoma and pineoblastoma)
CLINICAL FEATURES
- Most commonly afflicts children in the first decade of life (mean age, 3 years)
- No clear gender predilection
- Common presenting signs/symptoms
- Hydrocephalus: headache, nausea, vomiting, altered mental status, papilledema
- Parinaud syndrome (upgaze palsy)
- Absent serum tumor markers (differentiates from many germ cell tumors)
- Prognosis: poor prognosis; 5-year survival, ~50%
IMAGING FEATURES
- General
- Lobulated, poorly marginated pineal mass
- Might be indistinguishable from lower-grade pineal tumors
- Often larger and more invasive than pineocytomas
- Peripheral (“exploded”) calcifications common
- Commonly invades adjacent structures, including cerebral aqueduct, corpus callosum, thalamus, brainstem, and vermis
- Could see superior displacement of cerebral veins and mass effect on the tectum
- CT
- Heterogeneous density, irregular pineal mass
- Peripheral calcification
- Variable, patchy enhancement on contrast-enhanced CT imaging
- MRI
- T1WI: heterogeneously hypointense to isointense
- T2WI: heterogeneous signal; hyperintense peritumoral edema within the surrounding brain parenchyma common
- T1WI+C: heterogeneous enhancement
- DWI: diffusion restriction in solid component of mass common
- MRS: elevated Cho, decreased NAA
IMAGING RECOMMENDATIONS
- http://doi.org/10.1177/1051228405001514MRI 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
Cuccia V, Rodríguez F, Palma F, et al. Pinealoblastomas in children. Childs Nerv Syst 2006;22:577–585. doi.org/10.1007/s00381-006-0095-6.
Gasparetto EL, da Cruz LCH Jr, Doring TM, et al. Diffusion-weighted MR images and pineoblastoma: diagnosis and follow-up. Arq Neuropsiquiatr 2008;66:64–68. doi.org/10.1590/s0004-282x2008000100015.
Hirato J, Nakazato Y. Pathology of pineal region tumors. J Neurooncol 2001;54:239–249. doi.org/10.1023/a:1012721723387.
Nakamura M, Saeki N, Iwadate Y, et al. Neuroradiological characteristics of pineocytoma and pineoblastoma. Neuroradiology 2000;42:509–514. doi.org/10.1007/s002349900243.
Osborn AG, Salzman, KL, Jhaveri, MD. Diagnostic Imaging (3rd ed). Elsevier, Philadelphia, PA; 2016.
Reis F, Faria AV, Zanardi VA, et al. Neuroimaging in pineal tumors. J Neuroimaging 2006;16:52–58. doi.org/10.1177/1051228405001514.
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