PMC4040035_01
Sagittal T1-weighted brain magnetic resonance imaging showing an apparently intra-axial space-occupying lesion of the pontomedullary region (a) with subtle contrast enhancement (b), the lesion is hyperintense in axial T1-weighted images (c) and hypointense in T2-weighted images (d)
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F1
Brain MR imaging (MRI) demonstrated an atypical intra-axial pontomedullary lesion, which had a high T1 signal, a low T2 signal, and subtle contrast enhancement [Figure 1].
Magnetic resonance diffusion-weighted image revealing a bright signal within the tumor
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F2
For further confirmation, a diffusion-weighted imaging (DWI) sequence was obtained [Figure 2], which revealed a bright signal within the tumor suggestive of an epidermoid cyst rather than a cavernous malformation or brain tumor.
Postoperative computed tomography scans sagittal (a) and axial (b) demonstrate gross-total removal of the brainstem tumor
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F3
Postoperative computed tomography (CT) scan confirmed the intraoperative impression of gross-total removal [Figure 3], and histological testing confirmed the presence of an epidermoid cyst.