CNS & pituitary tumors
Gliomas, glioneuronal tumors, and neuronal tumors
Other astrocytic tumors
Subependymal giant cell astrocytoma
Author: Eman Abdelzaher, M.D., Ph.D.
Last author update: 1 March 2012
Last staff update: 19 March 2024 (update in progress)
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: Subependymal giant cell astrocytoma [title] (SEGA)
Table of Contents
Definition / general | Diagnosis | Radiology images | Case reports | Gross description | Microscopic (histologic) description | Positive stains | Negative stains | Differential diagnosisCite this page: Abdelzaher E. Subependymal giant cell astrocytoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cnstumorsubependymalgiantcell.html. Accessed May 14th, 2024.
Definition / general
- Benign, slowly growing tumor typically arising in wall of lateral ventricles and composed of large ganglioid astrocytes
- Usually associated with tuberous sclerosis, an autosomal dominant syndrome due to mutations in TSC1 gene on #9q34 (hamartin protein) and TSC2 gene on #16p13.3 (tuberin protein)
- WHO grade 1
Diagnosis
- Diagnostic criteria for tuberous sclerosis complex (TSC), modified from Roach et al. (J Child Neurol 1999;14:401)
Major features
- Facial angiofibromas or forehead plaque
- Nontraumatic ungual or periungual fibroma
- Hypomelanotic macules (more than 3)
- Shagreen patch (connective tissue nevus)
- Multiple retinal nodular hamartomas
- Cortical tuber
- Subependymal nodule
- Subependymal giant cell astrocytoma
- Cardiac rhabdomyoma, single or multiple
- Lymphangiomatosis
- Renal angiomyolipoma
Minor features
- Multiple randomly distributed pits in dental enamel
- Hamartomatous rectal polyps
- Bone cysts
- Cerebral white matter migration lines
- Gingival fibromas
- Nonrenal hamartomas
- Retinal achromic patch
- "Confetti" skin lesions
- Multiple renal cysts
- Definite TSC: either 2 major features or 1 major feature with 2 minor features
- Probable TSC: 1 major feature and 1 minor feature
- Possible TSC: either 1 major feature or 2 or more minor features
- Tuberous sclerosis also associated with pulmonary and uterine lymphangiomyomatosis, renal angiomyolipoma, cardiac rhabdomyoma
- SEGA present in 6% of tuberous sclerosis patients
Radiology images
Images hosted on other servers:
Enhancing mass in the third ventricle
Case reports
- 20 year old woman with solitary subependymal giant cell astrocytoma and mutation of TSC2 gene in tumor but not in somatic cells (J Mol Diagn 2005;7:544)
Gross description
- Circumscribed, often calcified
Microscopic (histologic) description
- Composed mainly of large polygonal to elongate cells resembling astrocytes or ganglion cells with abundant, finely granular eosinophilic cytoplasm, bright pink cellular processes, large round / oval nuclei, prominent nucleoli
- Perivascular pseudorosette formation is common
- Infiltration of mast cells and lymphocytes is common
- No Nissl substance in cytoplasm
- Presence of mitoses, vascular proliferation or necrosis does NOT indicate anaplastic progression
Positive stains
- Mixed glioneuronal phenotype
- GFAP+, S100+, also neurofilament proteins, neuronal associated class III β-tubulin
Negative stains
- HMB45 (unlike other tuberous sclerosis related lesions)
Differential diagnosis
- Ependymoma:
- SEGA cells are larger
- Gemistocytic astrocytoma:
- Intraparenchymal not intraventricular
