Angiocentric glioma

Initially identified in 2005 by Wang and his team from the University of Texas, AG was classified as Grade I by 2007 WHO Classification of Tumors of the Central Nervous System due to its benign clinical behavior, low proliferation index, and curative properties.

[3] Due to its short history of 15 years, the rarity of occurrence, and a lack of sufficient clinical trials, AG remains elusive on understanding symptoms, treatments, and long-term follow-up.

Till now, scientists and researchers have not found the exact etiology, definitive pathological tests for identification, and the effect of radiation or chemotherapy on this rare indolent glioma.

In terms of therapy, patients often undergo subtotal or total resection to remove the problematic lesion and have a relatively high likelihood of curing the disease.

[5] In 2005, Lellouch-Tubiana and his team analyzed 204 epilepsy surgery specimens histologically from patients aged 2 to 14 and discovered three very similar cases shown by Wang et al. in terms of pathological appearance and MRI results.

[4] Simultaneously in the same month in 2005, Wang et al. also published their further discoveries of five AG cases and indicated the specified histologic, immunohistochemical, and ultrastructural properties of this seizure-producing low growing tumor.

[8] Common symptoms also include headache, vision impairment, dizziness, otalgia, speech arrest, ataxia, and paresis, predominantly in children and young adults.

[10] Many studies on AG have prioritized neuroradiological features, clinical highlights, pathophysiology, and surgical treatment of this rare disease while lacking discussion on its causes.

[5] In the same year, another group of researchers suggested AG possibly derives from the neoplastic transformation of radial glial cells during neuronal migration as they present a similar proliferation pattern.

The research group proved that this protein alternation could be the critical contributor to AG oncogenicity since mice showed an enhanced cell proliferation rate after intracranial injection in experiments.

Researchers proposed that since AG does not acquire mutations of isocitrate dehydrogenase-1, making it have a lower recurrence potential after surgery compared to WHO grade II and III diffuse gliomas and secondary glioblastomas.

A clear indication of AG may appear as well-delineated, solid, T2-hyperintense, non-enhancing cortical lesions located in the temporal or frontal lobes in MRI.

The infiltrative AG cells display positive results for several immunostainings, especially the glial fibrillary acidic protein (GFAP) and epithelial membrane antigen (EMA).

[3] Other specific AG immunohistochemical tests include Ki-67 proliferative marker, neurospecific nucleoprotein (NeuN), protein 53, synaptophysin (Syn), oligodendrocyte transcription factor-2 (Olig-2) and creatine kinase (CK).

Photomicrograph displaying the AG tumor cells by histological evaluation, H&E stain . The striking characteristic of AG is that cells tend to cluster around brain blood vessels. [ 1 ]
MRI scan of a four-year-old boy with AG. The light grey part indicated a hyperintense and elastic lesion in his left posterior frontal lobe . [ 12 ]
The Computed Tomography scan (CT scan) is medical imaging machinery for body diagnostic using X-rays .
Magnetic Resonance Imaging (MRI) is a medical technique for capturing body images using radio waves .
Photomicrograph displaying the AG tumor cells by histological evaluation, H&E stain . Characteristics of AG: low Ki-67 proliferative rate, GFAP -positive, NeuN -positive, S-100 -positive, Protein53 -negative, Syn -negative, Olig-2 -negative, CK -negative. [ 3 ]