Book contents
- Frontmatter
- Contents
- List of contributors
- List of abbreviations
- Preface
- Section 1 Bilateral Predominantly Symmetric Abnormalities
- Section 2 Sellar, Perisellar and Midline Lesions
- Section 3 Parenchymal Defects or Abnormal Volume
- Section 4 Abnormalities Without Significant Mass Effect
- Section 5 Primarily Extra-Axial Focal Space-Occupying Lesions
- Section 6 Primarily Intra-Axial Masses
- 152 Acute Infarction
- 153 Glioblastoma Multiforme
- 154 Therapy-Induced Cerebral Necrosis (Radiation Necrosis)
- 155 Non-Hemorrhagic Metastases
- 156 Cerebral Abscess
- 157 Cerebral Toxoplasmosis
- 158 Primary CNS Lymphoma
- 159 Tumefactive Demyelinating Lesion
- 160 Tuberculoma
- 161 Oligodendroglioma
- 162 Low-Grade Diffuse Astrocytoma
- 163 Gliomatosis Cerebri
- 164 Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis, and Stroke-Like Episodes (MELAS)
- 165 Pleomorphic Xanthoastrocytoma (PXA)
- 166 Ganglioglioma
- 167 Neurocysticercosis – Parenchymal
- 168 Dilated Perivascular Spaces
- 169 Neuroepithelial Cyst
- 170 Subependymal Giant Cell Astrocytoma (SEGA)
- 171 Subependymoma
- 172 Ependymoma
- 173 Pilocytic Astrocytoma
- 174 Medulloblastoma
- 175 Hemangioblastoma
- 176 Lhermitte–Duclos (Cowden Syndrome)
- 177 Hypertensive Hematoma
- 178 Amyloid Hemorrhage – Cerebral Amyloid Angiopathy
- 179 Cortical Contusion
- 180 Hemorrhagic Neoplasms
- 181 Hemorrhagic Venous Thrombosis
- 182 Arteriovenous Malformation
- 183 Cavernous Angioma (Cavernoma)
- Section 7 Intracranial Calcifications
- Index
- References
171 - Subependymoma
from Section 6 - Primarily Intra-Axial Masses
Published online by Cambridge University Press: 05 August 2013
- Frontmatter
- Contents
- List of contributors
- List of abbreviations
- Preface
- Section 1 Bilateral Predominantly Symmetric Abnormalities
- Section 2 Sellar, Perisellar and Midline Lesions
- Section 3 Parenchymal Defects or Abnormal Volume
- Section 4 Abnormalities Without Significant Mass Effect
- Section 5 Primarily Extra-Axial Focal Space-Occupying Lesions
- Section 6 Primarily Intra-Axial Masses
- 152 Acute Infarction
- 153 Glioblastoma Multiforme
- 154 Therapy-Induced Cerebral Necrosis (Radiation Necrosis)
- 155 Non-Hemorrhagic Metastases
- 156 Cerebral Abscess
- 157 Cerebral Toxoplasmosis
- 158 Primary CNS Lymphoma
- 159 Tumefactive Demyelinating Lesion
- 160 Tuberculoma
- 161 Oligodendroglioma
- 162 Low-Grade Diffuse Astrocytoma
- 163 Gliomatosis Cerebri
- 164 Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis, and Stroke-Like Episodes (MELAS)
- 165 Pleomorphic Xanthoastrocytoma (PXA)
- 166 Ganglioglioma
- 167 Neurocysticercosis – Parenchymal
- 168 Dilated Perivascular Spaces
- 169 Neuroepithelial Cyst
- 170 Subependymal Giant Cell Astrocytoma (SEGA)
- 171 Subependymoma
- 172 Ependymoma
- 173 Pilocytic Astrocytoma
- 174 Medulloblastoma
- 175 Hemangioblastoma
- 176 Lhermitte–Duclos (Cowden Syndrome)
- 177 Hypertensive Hematoma
- 178 Amyloid Hemorrhage – Cerebral Amyloid Angiopathy
- 179 Cortical Contusion
- 180 Hemorrhagic Neoplasms
- 181 Hemorrhagic Venous Thrombosis
- 182 Arteriovenous Malformation
- 183 Cavernous Angioma (Cavernoma)
- Section 7 Intracranial Calcifications
- Index
- References
Summary
Specific Imaging Findings
Subependymomas are well-defined round to oval masses usually not exceeding 2 cm in greatest diameter that occur around the foramen of Monro and in the fourth ventricle. These neoplasms are hypodense on CT, of low to mildly increased T1 signal, and hyperintense on T2-weighted sequences, with characteristically very bright signal on FLAIR images. They are generally homogenous with absent or minimal focal contrast enhancement, although lobulated contours and intratumoral cysts may be encountered. Heterogenous signal intensities and/or internal calcifications are not unusual and some tumors may sho3w moderate to prominent enhancement on MR imaging. Diffusion of water molecules is higher than in the brain parenchyma resulting in high signal on ADC maps. Perfusion studies show very low blood volume. Subependymomas may very rarely arise in an intra-axial location, and even in those cases the presence of surrounding edema is an exception. MR spectroscopy shows normal choline peak and depressed NAA. Rare cases of recurrent subependymoma may demonstrate increased choline to creatine (Cho/Cr) ratio on MRS.
Pertinent Clinical Information
Subependymomas are rare, slow-growing, low-grade gliomas, the majority of which are asymptomatic and found incidentally at postmortem examination. They are typically associated with the ventricular system and become apparent clinically only when symptoms of hydrocephalus or mass effect develop. Their clinical features may vary widely, most commonly presenting with headache and vomiting in older adult patients.
- Type
- Chapter
- Information
- Brain Imaging with MRI and CTAn Image Pattern Approach, pp. 353 - 354Publisher: Cambridge University PressPrint publication year: 2012