Other Gliomas

Abstract

WHO Classification of tumors of the CNS, 2016 includes chordoid glioma of the third ventricle, angiocentric glioma, and astroblastoma in the other gliomas category. These are rare tumors. The chordoid glioma of the third ventricle has a typical location, affects commonly adults; and has a favorable prognosis. It is defined as a slow-growing, noninvasive glial tumor located in the third ventricle, histologically characterized by clusters and cords of epithelioid tumor cells expressing GFAP, within an invariably mucinous stroma typically containing lymphoplasmacytic infiltrate (WHO 2016). Chordoid gliomas exhibit strong and diffuse reactivity for GFAP and consistently express TTF1 nuclear immunoreactivity. Angiocentric gliomas defined as an epilepsy-associated, stable, or slow-growing cerebral tumor primarily affecting children and young adults; histologically characterized by an angiocentric pattern of growth, monomorphous bipolar cells, and features of ependymal differentiation (WHO 2016). These express GFAP and EMA dot positivity. Astroblastomas are defined as rare glial neoplasms composed of cells that are positive for GFAP and have broad, non- or slightly tapering processes towards central blood vessels (astroblastic rosettes) that often demonstrate sclerosis.

The chapter illustrates MR findings, histopathology, IHC pictures, and their features along with differential diagnosis for each of the above, genetic profile, and prognosis.