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
170 - Subependymal Giant Cell Astrocytoma (SEGA)
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
Subependymal giant cell astrocytomas (SEGAs) almost exclusively originate from the subependymal surface of the caudate nucleus, near the foramen of Monro, in patients with tuberous sclerosis complex (TSC). Bilateral lesions are common; they are often asymmetric both in size and growth rate. SEGAs are prevailingly solid, although cystic components may be present, especially in large masses. Lesions may show lobulated margins and resemble a conglomeration of nodules. Calcification is common, and is best seen on CT. The solid component is isointense with gray matter on all MR imaging sequences, and enhances homogeneously with gadolinium administration. The lesions are similar to the brain on diffusion imaging. Diameter over 12 mm, or a lesion more than 5 mm in size with growth on serial imaging are the characteristics indicative of SEGA. All lesions at the foramen of Monro in TSC patients should be presumed to be SEGA until proven otherwise. Contrast enhancement was considered a differentiating feature of SEGA on CT; however, many subependymal nodules enhance on MRI.
Pertinent Clinical Information
SEGA is found predominantly during the first and second decades of life, sometimes even in utero. The lesion may be asymptomatic per se; however, when sufficiently large it may obstruct CSF flow at the foramen of Monro, leading to elevated intracranial pressure and hydrocephalus. Worsening of epilepsy may lead to neuroimaging and diagnosis of SEGA. Neurosurgical resection is an effective standard treatment and may be performed before the lesions become symptomatic; however, SEGAs frequently recur.
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- Brain Imaging with MRI and CTAn Image Pattern Approach, pp. 351 - 352Publisher: Cambridge University PressPrint publication year: 2012