PMC9169718_01
Case 1: a 74-year-old man with squamous cell carcinoma. (A) Coronal fat-suppressed contrast-enhanced T1-weighted image shows a thickening, abnormally enhancing right C4 nerve (arrow). (B) Axial fat-suppressed contrast-enhanced T1-weighted image shows thickening and abnormal enhancement of the right C3 nerve, from the dorsal root ganglion through its course through the posterior cervical space (arrows).
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After 2 months of increasing numbness that extended to the right anterior upper chest wall and eventually to the jaw, MRI of the neck and shoulder in February 2021 showed asymmetric enhancement of the right C4 nerve just distal to the C3-C4 neural foramen ( Figure 1 ).
PMC9169718_02
Case 2: a 50-year-old woman with basosquamous carcinoma. (A) Coronal fat-suppressed contrast-enhanced T1-weighted image shows asymmetric enhancement along the superior orbit (arrow), adjacent to the superior rectus muscle. (B) Pre-operative forehead recurrence. (C) Intra-operative dissection of the distal sensitive branches of the forehead sensory nerves. (D) Defect of the forehead after resection of the recurrence with 2 cm margins. (E) Pathological sample. Red arrows showing the tagged distal sensory branches. 1 = right supraorbital nerve; 2 = right supratrochlear nerve; 3 = left supraorbital nerve dissected until its entrance in the superior orbital fissure. The left supratrochlear nerve is missing and was dissected separately as interrupted by a pre-operative biopsy. (F) Pre - and 14-month post-operative clinical photos. Post-operative proton radiotherapy spared the reconstructed forehead and focused on the retro-orbital and skull course of the supratrochlear nerve including the Gasser nerve.
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The left supra-orbital nerve was macroscopically enlarged in accordance with pre-operative MRI findings ( Figure 2 ).
PMC9169718_03
Case 3: an 81-year-old man with squamous cell carcinoma and perineural spread along V1 to the cavernous sinus. (A) MRI with coronal fat-suppressed T2-weighted image shows intermediate signal intensity tumor involving V1 (straight arrow) adjacent to normal superior rectus muscle (curved arrow). (B) Axial fat-suppressed contrast-enhanced T1-weighted image shows abnormal enhancement in the superior orbit (arrow). (C) Coronal contrast-enhanced T1-weighted image, obtained just posterior to the superior orbital fissure, shows asymmetric enhancement and fullness along the lateral margin of the cavernous sinus (arrow).
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MRI of the brain demonstrated a 1.0-cm soft tissue mass at the left superior orbital rim with tumor perineural extension along V1 into the left supraorbital foramen, left orbit, and left cavernous sinus ( Figure 3 ).
PMC9169718_04
Case 4: a 74-year-old-man with squamous cell carcinoma. (A) Axial fat-suppressed contrast-enhanced T1-weighted image shows a thickened, abnormally enhancing left V2 nerve extending from the premaxillary fat to the inferior cavernous sinus and along the left Vidian nerve (arrows). (B) Axial fat-suppressed contrast-enhanced T1-weighted image performed 6 months after permanently discontinuing pembrolizumab shows mild asymmetric enhancement of the left V2 nerve that is improved compared to pre-treatment (arrows).
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May 2018, the patient presented with left facial droop and noted that the numbness had now spread to the right side of his face. MRI of the brain demonstrated perineural tumor spread along the left V2 segment extending from the premaxillary fat to the inferior cavernous sinus and along the left Vidian nerve ( Figure 4 ).