Diagnóstico del schwannoma intracraneal del nervio facial. factores clínicos, radiológicos y valor de la inmunohistoquímica

Facial Schwannomas: Various Presentations and their Management with Literature Review

Facial schwannomas or neuromas are rare entity. They often are confused with vestibular schwannomas on imaging, especially if they are limited to the cisternal segment of the facial nerve. Awareness regarding this entity is paramount for the early diagnosis and correct management which may differ from patient to patient. We share the different clinical presentations of this rare benign tumour and discuss their management strategies in light of the affected segment of the nerve. The results were analyzed along with review of literature. Three cases of facial schwannomas were analyzed retrospectively during last 4 years and their presentation, imaging, preferred surgical approaches, intra-operative findings and post grafting results are discussed. All three patients underwent surgical excision with sural nerve cable grafting and have no recurrence till date. However, the facial paresis remained the same in one of the cases while improvement was observed in two patients. The improvement was delayed in one patient as documented by electromyography of facial muscles. Facial schwannomas are slow growing tumours with low incidence. Usual presentations can sometimes be masked. Appropriate management decision needs to be arrived after considering three determinants i.e. the patient's age, hearing status and the severity of facial paresis (House-Brackmann grading). Nerve reconstruction after excision should be performed in each case and sometimes the results may be delayed. It is thus important to keep a close surviellance during the follow up and to perform the electrophysiological tests frequently so as to detect the earliest signs of regeneration (which can be delayed up to 18 months).

Surgical treatment of patients with facial neuromas--a report of 26 consecutive operations

OBJECTIVE

To analyze surgical treatment and outcome in patients with facial neuromas at a tertiary referral hospital.

STUDY DESIGN

A chart review of 26 patients treated between 1971 and 2006, with questionnaire follow-up ranging from 2 to 19 years. All patients except one were operated with radical tumor removal approaches.

RESULTS

Approximately 54% of the patients presented with symptoms related to the VIIth cranial nerve (facial palsy and facial spasm), 58% with symptoms related to the VIIIth cranial nerve (hearing deficit, tinnitus, and vertigo), and 8% related to the Vth cranial nerve (facial pain and facial sensory deficit). Approximately 39% presented with no facial symptoms. Twenty-one patients received a facial nerve graft from the greater auricular nerve or the sural nerve; 1 patient had an accessory-facial anastomosis. One patient had a subtotal tumor removal preserving the facial nerve. Three patients were not grafted. Most tumors (88%) affect the geniculate ganglion. Approximately 82% of the grafted patients regained a House-Brackmann facial nerve function (HB) grade III; 14% regained HB grades IV to V. No serious morbidity or mortality was reported. No recurrences have been reported where a total tumor removal was performed.

CONCLUSION

Surgical removal of facial neuroma is a safe procedure with a low complication rate and a low recurrence rate. First symptoms are diverse and are predominantly derived from the facial and vestibulocochlear nerve. Facial nerve grafting is reliable, giving the patient an acceptable facial nerve function (HB III).

Facial Nerve Schwannoma Presenting as a Mass in the Middle Cranial Fossa: Typical Neuroradiological Patterns for a Preoperative Diagnosis

Facial nerve schwannoma is a rare primary neurogenic tumour that may originate anywhere along the VIIth nerve course. The clinical presentation is highly dependent on the location of the lesion along the nerve course and this makes the pre-operative diagnosis difficult without radiologic examination. The most common presentation is facial palsy and even though tumours are responsible for only 5% of facial palsies, if a patient does not recover within six months a complete work-up for neoplasm is recommended. On the basis of clinical presentation and imaging characteristics radiologists should try to make a preoperative diagnosis, to help in the patient's management and possibly to plan the surgical approach. We describe the case of a successful preoperative diagnosis of facial nerve schwannoma. The aim is to describe the main CT and MRI findings which may help the radiologist to establish a correct differential diagnosis.