[Perineural tumor spread from the ophthalmic branch of the trigeminal nerve: a case report]

Perineural tumor spread of head and neck malignancies is a well known form of metastatic disease in which a lesion can migrate away from the primary site along the cranial nerves. Nerve function can be preserved even in advanced stages of the disease, making neuroradiological assessment of perineural tumor location and extension of utmost importance, as radiological or pathological examination may reveal normal or nonspecific nerve function. Computed Tomography is useful in detecting foraminal enlargement or more destructive bone patterns. Magnetic Resonance imaging is the modality of choice because it can provide direct (nerve enlargement and enhancement) and indirect evidence of the disease (neuropathic muscular atrophy, obliteration of fat planes) owing to its superior soft-tissue contrast resolution, its multiplanar imaging and the decreased amount artifacts from dental hardware. Fat suppression images after contrast injection are mandatory to better detect nerve enhancement. We report the case of a female patient with perineural diffusion along the ophthalmic branch. This clinical picture is very rare, compared to those involving the mandibular and maxillary branches of the fifth cranial nerve.