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Left V1 Perineural Spread of Squamous Cell Carcinoma in an Elderly Woman
An elderly woman with a history of left forehead squamous cell carcinoma and forehead numbness is found to have left V1 perineural spread.
Imaging overview:
Coronal T1, coronal T2 fat-suppressed, and post-contrast fat-suppressed T1 MRI show abnormal findings in the left supraorbital region that are not present on the right. The arrows mark the left supraorbital nerve region, where the nerve appears abnormal on all three sequences, with enhancement on the post-contrast image.
Clinical insight:
Perineural spread of tumor, most often from cutaneous squamous cell carcinoma, should be considered in any patient with a history of skin cancer and new cranial nerve symptoms. Numbness in the V1 distribution, such as the forehead, is a clinical clue that warrants MRI of the orbit and skull base. Typical MR findings include nerve thickening, abnormal enhancement, widening of the associated foramen, and loss of perineural fat. Branches of CN V and CN VII are most commonly involved, and an accurate clinical history helps direct the imaging.
Case courtesy of Nancy Fischbein, MD, Stanford University.