CNS tumor
Astrocytic tumors
Subependymal giant cell astrocytoma (SEGA)

Author: Eman Abdelzaher, M.D., Ph.D. (see Authors page)

Revised: 28 August 2017, last major update March 2012

Copyright: (c) 2002-2017, PathologyOutlines.com, Inc.

PubMed Search: Subependymal giant cell astrocytoma [title] (SEGA)

Cite this page: Abdelzaher, E. Subependymal giant cell astrocytoma (SEGA). PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/cnstumorsubependymalgiantcell.html. Accessed September 24th, 2017.
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 I
Diagnosis

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:

Various images

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
Microscopic (histologic) images

Images hosted on other servers:

Large cells with abundant cytoplasm and prominent nucleoli

NSE

Positive stains
Negative stains
  • HMB45 (unlike other tuberous sclerosis related lesions)
Differential diagnosis