Delayed Facial Nerve Palsy Developing After Surgery for a Benign Parotid Gland Tumor

Facial nerve palsy is the most serious complication to be aware of in surgery for parotid gland tumors. It occurs due to various factors including direct intraoperative injury, traction, thermal injury, ischemia, and anatomical variations. While most cases occur immediately after surgery, some may develop within the first 24 to 72 hours due to postoperative edema or hematoma. Delayed facial nerve paralysis occurring more than 72 hours after surgery is extremely rare. We report a case of a 60-year-old woman who developed delayed facial nerve palsy 16 days after parotid gland surgery. Mild paralysis of the lower lip was observed postoperatively, but no abnormalities were detected in other facial muscles. The postoperative course was uneventful, and the patient was discharged on the eighth day. However, on the 10th day after the surgery, pain appeared around her ear, and severe facial nerve paralysis developed on the 16th day. Pain was present from the ear to the scalp of the temporal region, but no objective findings such as postoperative infection, edema, hematoma, or tumor recurrence were observed. The patient received combined therapy with steroids and antiviral agents based on the treatment for idiopathic facial nerve palsy, and the paralysis fully recovered after four months. Delayed facial nerve palsy following parotid gland tumor surgery is extremely rare, and it is important to investigate causative factors before initiating treatment.