PMC4244770_01
Lesion (yellow arrow) is mixed in intensity (Hypo to isointense) on T1-weighted sagittal image. (a) Lesion is heterogeneously contrast enhancing on sagittal image and (b) coronal image (c) on T1-weighted contrast image. On A,B,C images, the lesion was predominantly expanding the fourth ventricle and extending inferiorly through the foramen magnum into the upper cervical canal till C3 vertebra level on left side displacing the medulla and cervical spinal cord anteriorly and to the right side. T2-weighted axial image the lesion is predominantly hyperintense with areas within of iso-intensity filling the fourth ventricle (d)
JNRP-6-112-g002.jpg
PMC4244770_01_JNRP-6-112-g002.jpg
F1
It was found extending inferiorly through the foramen magnum into the upper cervical canal till C2 vertebra level displacing the medulla and cervical spinal cord anteriorly and to the right side [Figure 1].
Tumor extending from vermis through the foramen magnum into the upper cervical. (a) Spinal accessory nerve origin of lesion. (b) Post excision visualization of the fourth ventricle (labeled) and thespinal accessory nerve trunk free of attachment (marked FNx01) and the cervical cord (marked as X). (c) Postoperative CT scan showing tumor clearance (d)
JNRP-6-112-g003.jpg
PMC4244770_01_JNRP-6-112-g003.jpg
F2
The lesion was found arising from the trunk of the left spinal accessory nerve at the level of the foramen magnum [Figure 2b]. The lesion was extending from C2 and into the fourth ventricle below the vermis, pushing the upper cervical cord and cervicomedullary junction to the right [Figure 2a]. The lesion was excised along with the embedded segment of the nerve, preserving the uninvolved portion which was draped over the tumor [Figure 2c]. His post-operative contrast CT scan showed no residual lesion with resolving hydrocephalus [Figure 2d].