Gemistocytic astrocytoma
Gemistocytic astrocytoma is a histologic subtype of low grade astrocytoma, with a poorer prognosis than other matched WHO grade tumors, and with no specific imaging features.
For a general discussion of clinical presentation, epidemiology, treatment please refer to the article on low grade astrocytomas.
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Pathology
Gemistocytic astrocytomas are characterized by a significant gemistocytes population, which are large cells with their cytoplasm filled with eosinophilic material displacing the nucleus eccentrically 1.
It is important to note that other gliomas (e.g. fibrillary astrocytoma and oligodendrogliomas) can have occasional gemistocytes, without being designated a gemistocytic astrocytoma. Some authors use a cut off of 20% of the tumor cells being gemistocytes before designating it as a gemistocytic astrocytoma 1-2.
Radiographic features
Although there are no specific features which allow pre-biopsy diagnosis, gemistocytic astrocytomas are almost always supratentorial and usually located in the frontal lobes 4.
Treatment and prognosis
In general gemistocytic astrocytomas, although often still considered WHO II tumors, have a more aggressive behavior compared to fibrillary astrocytomas 1-3. Some authors suggest that they should be considered WHO III tumors 2.
The median with treatment is only 2.5 years, with a 5-year survival rate of 30% which is significantly worse than other low grade gliomas 4. Older age at presentation appears to be a poor prognostic sign 4.
Given the generally worse prognosis, most clinicians would favor a more aggressive approach to treatment.
Related Radiopaedia articles
Astrocytic tumour
-
astrocytic tumors
- WHO classification of CNS tumors
- WHO grading of CNS tumors
- VASARI MRI feature set
- diffuse astrocytoma grading
- grade I:
- grade II:
- chordoid glioma of the third ventricle
-
low-grade diffuse astrocytoma
- fibrillary astrocytoma (no longer recognized)
- protoplasmic astrocytoma (no longer recognized)
- gemistocytic astrocytoma
- oligoastrocytoma
- pilomyxoid astrocytoma
- pleomorphic xanthoastrocytoma
- grade III
- grade IV:
-
glioblastoma (GBM)
- glioblastoma IDH wildtype
- glioblastoma IDH mutant
- glioblastoma NOS
- variants
- diffuse midline glioma H3 K27M–mutant
-
glioblastoma (GBM)
- glioblastoma vs cerebral metastasis
- radiation-induced gliomas
- gliomatosis cerebri (growth pattern)
- specific locations
- treatment response
- prognostic genetic markers