When the Bell Tolls on Bell's Palsy: Finding Occult Malignancy in Acute-onset Facial Paralysis

Purpose: This study reports 4 cases of occult parotid malignancy presenting with sudden-onset facial paralysis to demonstrate that failure to regain tone 6 months after onset distinguishes these patients from Bell's palsy patients with delayed recovery and to propose a diagnostic algorithm for this subset of patients.

Materials And Methods: A case series of 4 patients with occult parotid malignancies presenting with acute-onset unilateral facial paralysis is reported.

Results: Initial imaging on all 4 patients did not demonstrate a parotid mass. Diagnostic delays ranged from 7 to 36 months from time of onset of facial paralysis to time of diagnosis of parotid malignancy. Additional physical examination findings, especially failure to regain tone, as well as properly protocolled radiologic studies reviewed with dedicated head and neck radiologists, were helpful in arriving at the diagnosis.

Conclusion: An algorithm to minimize diagnostic delays in this subset of acute facial paralysis patients is presented. Careful attention to facial tone, in addition to movement, is important in the diagnostic evaluation of acute-onset facial paralysis.