A case of tanycytic ependymoma arising from the cerebral hemisphere

Abstract

We report a rare case of tanycytic ependymoma arising from the cerebral hemisphere. A 59-year-old man was admitted to our hospital because of the incidental detection by MRI of a tumor lesion in the right temporooccipital paratrigonal region. The mass showed low-to iso-intensity on T1-weighted images and high intensity on T2/proton-weighted images. Partial resection was performed using a transsulcal approach to avoid compromising the visual field. Most of the tumor cells showed elongated spindle shapes arranged in dense fascicles. A few true ependymal rosettes and perivascular pseudorosettes were visible. The tumor cells were positive for GFAP, S-100, and vimentin, but negative for synaptophysin, EMA, and keratin. The MIB-1 labeling index was approximately 1%. Ultrastructurally, the tumor cells had ependymal cell features, such as microvilli and cilia. From these findings, a pathological diagnosis of tanycytic ependymoma was made.

Tanycytic ependymoma arising from the right lateral ventricle: A case report and review of the literature

“…No obvious gender difference was found, male patients being slightly more than female and M : F ratio being 1.2 : 1.0. Interestingly, all four patients reported suffering from supratentorial extraventricular mass were male 3–6 . Including the present case, four cases of TEs have arisen from the lateral ventricle (Table 2).…”

“…Interestingly, all four patients reported suffering from supratentorial extraventricular mass were male. [3][4][5][6] Including the present case, four cases of TEs have arisen from the lateral ventricle (Table 2). [7][8][9] Neuroradiologically, they are cystic or solid-cystic masses involving occasional brain tissue in the vicinity of or in the third ventricle.…”

“…Electron microscopy (EM) can aid in distinguishing TEs from other tumors if diagnosis is in doubt. EM of these tumors shows characteristic ependymal features including intracytoplasmic intermediate filaments, prominent intercellular junctions, numerous slender surface microvilli, and microvilli‐lined lumina, but no basement membrane in aggregated tumor cells 4,6,8,15 …”

“…Twenty-nine TEs have been reported. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Patient ages at diagnosis ranged from 6 to 62 years (mean, 36.0; median, 39 years). TEs occur frequently in spinal cord (65.5%, 19/29) followed by intraventricle (20.7%, 6/29) and supratentorial extraventricle (13.8%, 4/29) ( Table 1).…”

Tumours of the Central Nervous System

“…Ultrastructurally, the clear cells display ependymal rather than oligodendroglial differentiation. Tanycytic ependymomas are composed of elongated spindle cells arranged in fascicles somewhat reminiscent of those of pilocytic astrocytomas (Ito et al, 2006). However, those bundles are accompanied by true ependymal rosettes and perivascular pseudorosettes, albeit with a lower frequency than in classical ependymomas.…”