Analysis of clinical diagnosis and treatment of 12 cases of intraparotid facial nerve schwannoma

Abstract

Objective: To investigate the clinical manifestation and management strategy of intraparotid facial nerve schwannoma. Methods: The clinical data of 12 patients with parotid schwannoma treated in Henan Cancer Hospital from January 2009 to January 2019 were analyzed retrospectively, including 5 males and 7 females, aged from 23 to 72 years. All the 12 patients complained of a mass in the parotid region, of whom 4 patients had local discomfort and pain, and 6 patients had varying degrees of pain during palpation. Ultrasound examination showed solid mass in parotid region in 8 cases and mixed mass in 4 cases. The treatment methods, the relationship between tumor and facial nerve, the modes of treatments and the nerve functions before and after operation were analyzed and summarized with House-Brackmann grade. Results: All 12 patients received surgical treatment: 8 patients underwent tumor resection plus partial or total superficial parotidectomy, 1 patient underwent tumor resection and total parotidectomy, and 3 patients underwent tumor resection, with 1 patient in whom tumor could not be removed completely due to tumor extention to the skull base. In 9 cases, the tumor occurred in the trunk or main branch of the facial nerve, and there was no facial nerve injury occurred after surgery; in 1 case, the tumor occurred in the terminal branch of the facial nerve, and part of the severe small branches of adhesion were cut off during the operation; in 1 case, the total trunk of the facial nerve was not found and the broken end of the nerve could not be found during the operation, so the nerve transplantation was not performed. In 1 case, nerve grafting was performed after nerve transection because it was impossible to separate the trunk of the facial nerve from the tumor during the operation. Preoperatively, House-Brackmann grade (H-B)Ⅰfacial nerve function was shown in 10 patients, H-BⅡ in 1 patient and H-B Ⅴin 1 patient. Postoperatively, the facial nerve function recovered to H-B Ⅰfor 7 patients, H-B Ⅱfor 2 patients, H-B Ⅲ for 1 patient, grade Ⅳ for 1 patient with nerve transplantation, and H-B Ⅴfor 1 patient with a revised surgery due to tumor recurrence. Conclusions: The intraparotid facial nerve schwannoma is rare, and it is easy to be misdiagnosed before operation. Surgery is a main treatment for intraparotid facial nerve schwannoma. Attention should be paid to the protection of facial nerve during operation.