Auriculotemporal Nerve Involvement in Parotid Bed Malignancy

Objective: To identify and evaluate patients with parotid bed malignancy demonstrating radiographic findings of auriculotemporal (AT) nerve involvement. Methods: A retrospective review of patients with parotid bed malignancy was performed to identify patients with imaging findings of AT nerve involvement and record associated clinical findings, symptoms, and pathology information. Independent, blinded review of radiographic images by a senior neuroradiologist was performed to identify imaging characteristics and categorize patients into highly likely or possible involvement groups. Results: Of 547 patients identified with parotid bed malignancy, 23 patients exhibited radiographic findings suggestive of AT nerve involvement. Thirteen patients met criteria for highly likely involvement, and 10 patients met criteria for possible involvement. Cutaneous malignancy with metastasis to the parotid bed accounted for 11 of 23 patients, and the most common histology was squamous cell carcinoma (9 patients). Primary parotid malignancy accounted for 12 of 23 patients, and the most common histology was salivary ductal carcinoma (3 patients). All 13 highly likely patients reported periauricular pain, and 11 of 13 demonstrated facial weakness. Features suggesting advanced disease included radiographic findings of intracranial involvement (10/23 patients), nonsurgical primary treatment (13/23 patients), and positive margins on pathology report (7/10 patients). Conclusion: AT nerve involvement is an uncommon but important phenomenon that often occurs in the setting of advanced disease and is commonly associated with periauricular pain and coexisting facial weakness. Awareness of the associated clinical features and imaging patterns can allow for appropriate identification of this pattern of spread and help to optimize treatment planning.