Perineural tumor spread along the nasociliary branch of the ophthalmic nerve: imaging findings.

Perineural spread along the nasociliary branch of the ophthalmic nerve has not been previously described, to our knowledge. One case of cutaneous squamous carcinoma at the medial canthus and another of melanoma of the nasal ala, with nasociliary nerve perineural spread, are illustrated here. Whereas magnetic resonance imaging is preferred to search for perineural spread, computed tomography may also demonstrate perineural thickening and enhancement. Awareness of the computed tomography appearance of perineural spread will aid in avoiding misdiagnosis.