Table of Contents
Definition / general | Terminology | Epidemiology | Sites | Grading | Radiology description | Radiology images | Prognostic factors | Case reports | Treatment | Clinical images | Gross description | Microscopic (histologic) description | Positive stains | Negative stains | Electron microscopy description | Differential diagnosisCite this page: Abdelzaher E. Chordoid glioma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cnstumorchordoidglioma.html. Accessed April 23rd, 2024.
Definition / general
- Rare, discrete, slow growing glial tumor of third ventricle of adults, characterized by chordoid architecture and myxoid background
- First described in 1998 (J Neuropathol Exp Neurol 1998;57:283)
- Cells may resemble ependyma of subcommissural organ, present in dorsocaudal third ventricle during embryonic life, which regresses after birth
Terminology
- "Glioma" since GFAP+
Epidemiology
- Uncommon ( < 50 cases reported)
- Usually middle aged women (median age 45 years, 63% female)
Sites
- Low grade neoplasm arising in third ventricle hypothalamic region
- Often attached to hypothalamic and suprasellar structures (63%)
Grading
- WHO grade 2
- WHO 2000 lists as "glial tumor of uncertain origin"
Radiology description
- Well circumscribed, solid, enhancing mass, 19% are cystic (AJNR Am J Neuroradiol 2001;22:464)
Radiology images
Prognostic factors
- May have poor outcome despite bland histology (Am J Surg Pathol 2002;26:1330, Neuropathol Appl Neurobiol 2005;31:354)
Case reports
- 48 year old man with gradual diminution of vision (Neurol India 2011;59:469)
- 48 year old woman with suprasellar tumor coexisting with Rathke cleft cyst (Pathol Int 2003;53:780)
- 50 year old woman with chordoid glioma infiltrating optic chiasm (Surg Neurol Int 2011;2:53)
- 56 year old woman (Arch Pathol Lab Med 2004;128:e141)
- 60 year old woman (Hum Pathol 1999;30:723)
Treatment
- Resection; rarely radiotherapy (Surg Neurol 2003;59:424), occasionally recurs due to incomplete excision (16%)
Gross description
- Discrete firm mass adherent to wall of third ventricle
Microscopic (histologic) description
- Chordoma-like features
- Clusters and cords of epithelioid cells in mucinous matrix
- Cells have abundant eosinophilic cytoplasm and round / oval nuclei with indistinct nucleoli
- Also lymphoplasmacytic infiltrates, Russell bodies, discrete border with peritumoral piloid gliosis
- May have chondroid metaplasia or papillary formations
- No / rare mitotic figures, no vascular proliferation, no necrosis
Positive stains
- GFAP, vimentin, CD34, EMA (focal), cytokeratin (focal) (Brain Pathol 1999;9:617)
- Low Ki67 index
- Variable S100
Negative stains
- Synaptophysin, neurofilament (usually), NSE (usually), desmin, p53
Electron microscopy description
- Ependymal differentiation
- Apical pole has microvilli and basal pole has hemidesmosome-like structures connecting cell membranes to basal lamina
- Also submicroscopic cell body zonation and secretory granules (Am J Surg Pathol 2001;25:401)
Differential diagnosis
- Chordoid meningioma: whorls, psammoma bodies and nuclear pseudoinclusions, EMA+, GFAP-, well formed desmosomes, 22q-
- Chordoma: infiltrates bone, physaliphorous cells, EMA+, diffusely keratin+, S100+, GFAP-, mitochondria rough ER complexes