Angiocentric gliomas are rare superficial slow-growing brain tumors typically presenting in young patients with intractable partial epilepsy 1-6. They were first introduced in the 2007 (4th) edition of the WHO brain tumor classification, and are classified as WHO grade I tumors 1.
For a general discussion of clinical presentation, epidemiology, and treatment, please refer to the article on low-grade astrocytomas.
Angiocentric gliomas are very rare tumors with relatively few reported cases. They usually affect children and young adults 1,6. No reported gender predilection has been reported 1.
Seizures are the classical presentation, with over 95% of patients presenting with intractable seizures 3.
Angiocentric gliomas are designated as WHO grade I tumors 1-3. The exact etiology of angiocentric gliomas remains unclear although some features are similar to ependymomas 1,6. In fact, sometimes, a distinct ependymoma component may co-exist 1.
These tumors demonstrate a monomorphic population of elongated spindle-shaped bipolar cells with a strikingly perivascular orientation, somewhat reminiscent to perivascular pseudorosettes 1,6. Although tumor cells do extend into the surrounding parenchyma, a strong predilection for perivascular spread is evident 6. Subpial growth along the surface of the cortex is also a prominent feature 1,6.
The immunophenotype shares some similarities to ependymomas 1.
Ki-67 index is usually <5% 1.
Cortical dysplasia may be associated.
Angiocentric gliomas are usually cortical or subcortical (grey-white matter junction), typically well-delineated, supratentorial tumors that tend to expand affected gyri. They exhibit a propensity to spread horizontally in the subpial plane and deeply along vessels 1.
Typically appear as an expansile non-enhancing cortical tumor.
- hyperintense rim may be seen
T2 / FLAIR
- extension toward the ventricles along vessels
- may have cystic-appearing areas
- T1 C+ (Gd): no enhancement
History and etymology
Angiocentric glioma was initially identified in 2005 in two separate case reports 2,5 and then introduced in the WHO classification of CNS tumors in 2007. It remains an entity in the current (2016) WHO classification 1.
Given their rarity, on purely imaging grounds it is difficult to distinguish these tumors from more common diffuse gliomas (both astrocytoma and oligodendroglioma). Other imaging differential considerations include:
- focal cortical dysplasia
- cortical tuber (forme fruste of tuberous sclerosis)
- "bubbly" cortical and subcortical lesion
- rim of high signal on FLAIR
- minimal surrounding edema
- total nulling on the FLAIR sequence
- usually enhance
- well defined
multinodular and vacuolating neuronal tumors
- subcortical cluster of cystic-like lesions
- 1. Louis DN, Ohgaki H, Wiestler OD, Cavenee WK "WHO Classification of Tumours of the Central Nervous System. 4th Edition Revised" ISBN: 9789283244929
- 2. Wang M, Tihan T, Rojiani AM et-al. Monomorphous angiocentric glioma: a distinctive epileptogenic neoplasm with features of infiltrating astrocytoma and ependymoma. J. Neuropathol. Exp. Neurol. 2005;64 (10): 875-81. Pubmed citation
- 3. Osborn AG, Salzman KL, Thurnher MM et-al. The new World Health Organization Classification of Central Nervous System Tumors: what can the neuroradiologist really say?. AJNR Am J Neuroradiol. 2012;33 (5): 795-802. AJNR Am J Neuroradiol (full text) - doi:10.3174/ajnr.A2583 - Pubmed citation
- 4. Shakur SF, McGirt MJ, Johnson MW et-al. Angiocentric glioma: a case series. J Neurosurg Pediatr. 2009;3 (3): 197-202. doi:10.3171/2008.11.PEDS0858 - Free text at pubmed - Pubmed citation
- 5. Lellouch-Tubiana A, Boddaert N, Bourgeois M et-al. Angiocentric neuroepithelial tumor (ANET): a new epilepsy-related clinicopathological entity with distinctive MRI. Brain Pathol. 2006;15 (4): 281-6. Pubmed citation
- 6. Frangoise Gray, Charles Duyckaerts, Umberto De Girolami. Escourolle and Poirier's Manual of Basic Neuropathology. ISBN: 9780199929054
Related Radiopaedia articles
- WHO classification of CNS tumors
- WHO grading of CNS tumors
- VASARI MRI feature set
- diffuse astrocytoma grading
- grade I:
- grade II:
- grade III
- grade IV:
- glioblastoma vs cerebral metastasis
- radiation-induced gliomas
- gliomatosis cerebri (growth pattern)
- specific locations
- treatment response
- Stupp protocol
- glioma treatment response assessment in clinical trials
- multicentric glioblastoma
- multifocal glioblastoma
- prognostic genetic markers