Fig. 8.

A 60-year-old man with a history of nasopharyngeal carcinoma, previously treated with radiotherapy, presented with right neck pain and right upper limb weakness. On MRI, an infiltrative mass posterior to the carotid vessels on the right side of the neck was seen, which encased the exiting C3 to C5 nerve roots. (a) Coronal T1-W sequence image shows hypointensity (white arrow) and (b) axial T2-W sequence image shows heterogeneous hyperintensity (black arrow). (c) Axial T1-W image shows infiltration of the right C5 nerve root (white arrow) and an unaffected left C5 nerve root, in comparison (black arrowhead). Axial T2-W images show soft-tissue infiltration causing expansion of the right C5 neural foramen (white arrowheads in b & d). Given the history of nasopharyngeal carcinoma, these findings are consistent with malignant infiltration of the right brachial plexus, which was confirmed on histology. T1-hypointense lesions (in a) in C3, C4 and T2 vertebrae are compatible with bony metastases. Normal flow signal in the right internal jugular vein is not seen, suggestive of compression (in b & c).