Perineural tumor spread along the auriculotemporal nerve.

BACKGROUND AND PURPOSE Evaluation of images of perineural tumor spread in patients with head and neck malignancies is essential for planning treatment and determining the patient's prognosis. Although the communications between the facial and trigeminal nerves are not widely known, they may provide a route for tumor growth. The purpose of this study was to elucidate the course of the auriculotemporal nerve, as well as the clinical and imaging findings that suggest involvement of the communication between the facial nerve and the mandibular division (V(3)) of the trigeminal nerve. METHODS Images in 15 patients with clinical or radiologic findings suggestive of perineural tumor spread along the auriculotemporal nerve were reviewed. Involvement of the main trunk of the facial nerve, auriculotemporal nerve, V(3), trigeminal cistern, and ganglion and adjacent anatomic structures were noted in each patient. RESULTS The course of the auriculotemporal nerve was described in detail. More than 50% of patients with perineural tumor spread along the auriculotemporal nerve had clinical signs of auriculotemporal nerve dysfunction, including periauricular pain and temporomandibular joint (TMJ) dysfunction or tenderness. Images in 13 of 15 patients with such tumor spread demonstrated findings of tumor growth along V(3.). CONCLUSION Knowledge of the course of the auriculotemporal nerve is critical in evaluating images for findings of tumor spread along this nerve. Periauricular pain, TMJ dysfunction or tenderness, and imaging signs of V(3) involvement are important indicators of potential involvement of the auriculotemporal nerve.