MRI Characteristics of Ependymoblastoma: Results from 22 Centrally Reviewed Cases

Abstract

BACKGROUND AND PURPOSE:Ependymoblastoma is a malignant embryonal tumor that develops in early childhood and has a dismal prognosis. Categorized by the World Health Organization as a subgroup of CNS-primitive neuroectodermal tumor, ependymoblastoma is histologically defined by "ependymoblastic rosettes." Because it is so rare, little is known about specific MR imaging characteristics of ependymoblastoma. We systematically analyzed and discussed MR imaging features of ependymoblastoma in a series of 22 consecutive patients.

Embryonal Tumors of the Central Nervous System: From the Radiologic Pathology Archives

“…Similar to AT/RTs, they are often isoattenuating to hyperattenuating and heterogeneous at CT with internal cysts or calcifications (85). They are also hypercellular and heterogeneous at MR imaging, with isointense to hyperintense T2 signal, restricted diffusion at diffusion-weighted imaging/ADC mapping, and internal necrosis or hemorrhage (86).…”

“…Ependymoblastoma/ETMR specifically tends to be large with well-defined margins at presentation and also more commonly displays mild or no enhancement rather than strong enhancement ( Fig 10); increased cerebral blood volume (CBV) at perfusion imaging may result from vascular endothelial hyperplasia (86). There is significant overlap in the MR imaging appearance of ependymoblastoma/ETMR and other CNS PNET/embryonal tumors, as well as highgrade supratentorial ependymoma (87).…”

Clinical and magnetic resonance imaging findings of a cerebellar medulloblastoma in a heifer

“…Equally ependymoma was considered a possible differential diagnosis given the MRI characteristics; however, this type of tumor has been more commonly reported in adult patients in the veterinary literature . Ependymoblastoma has only been reported once in cattle, and its MRI features have been recently described in humans consisting of well‐defined tumor margins, iso‐ to hyperintense tumor signal relative to gray matter on T2‐weighted images, mainly hypo‐ to isointense signal on T1‐weighted images although different signal intensities (hypo‐/iso‐/hyperintense) can be found due to partial hemorrhage and calcifications, and mild to moderate contrast enhancement . Although ependymoblastoma was considered compatible with our findings, it was deemed less likely in view of its rarity.…”

Embryonale Tumoren des Zentralnervensystems

“…In der MRT-Bildgebung stellen sie sich hyperzellulär und heterogen mit iso-bis hyperintensem T2w Signal, mit Diffusionsrestriktion in der DWI bzw. ADC-Kartierung und mit interner Nekrose oder Blutung dar [86].…”

“…10). Ein erhöhtes zerebrales Blutvolumen in der Perfusionsbildgebung kann von einer vaskulären endothelialen Hyperplasie herrühren [86]. Die MRT-Befunde von Ependymoblastomen bzw.…”