title: Symptomatic child case of subependymoma in the fourth ventricle without hydrocephalus.
abstract: We report a rare child case of symptomatic subependymoma in the fourth ventricle without hydrocephalus. The upper half of the tumor was demonstrated as a non-enhancing isodense mass with punctate calcification on CT, whereas the lower portion showed slightly irregular ring-like enhancement with a central hypodense area. The tumor was heterogeneously hyperintense on T2-weighted magnetic resonance (MR) images. When scanned with a T1-weighted sequence, the upper portion of the tumor was isointense to brain, but the lower portion was hypointense. However, using Gd-enhanced T1-weighted imaging, such as in postcontrast CT, the upper portion did not enhance, whereas the lower portion revealed similar ring-like enhancement, which was suggestive of necrosis. To further confirm the nature of the tumor, a diffusion-weighted imaging study with echo-planar technique was performed, and it indicated the solid nature of the tumor, which was confirmed histopathologically.
authors: Department of Radiology, Niigata University Faculty of Medicine, Japan.
authors: G I
authors: GI
authors: Fontenele
authors: K
authors: K
authors: Okamoto
authors: J
authors: J
authors: Ito
authors: A
authors: A
authors: Kakita
authors: H
authors: H
authors: Mori
authors: Y
authors: Y
authors: Toyoshima
authors: K
authors: K
authors: Sakai
authors: K
authors: K
authors: Ishikawa
mesh_terms: D001932:Brain Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D002648:Child; D003287:Contrast Media; D020546:Fourth Ventricle; D005682:Gadolinium; D018315:Glioma, Subependymal / Q000175:diagnosis* / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography
chemical_list: D003287:Contrast Media; D005682:Gadolinium