Facial nerve schwannomas presenting as occluding external auditory canal masses: a therapeutic dilemma

Task force of the Brazilian Society of Otology - evaluation and management of peripheral facial palsy

OBJECTIVE

To review key evidence-based recommendations for the diagnosis and treatment of peripheral facial palsy in children and adults.

METHODS

Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on peripheral facial palsy were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions.

RESULTS

The topics were divided into 2 main parts: (1) Evaluation and diagnosis of facial palsy: electrophysiologic tests, idiopathic facial palsy, Ramsay Hunt syndrome, traumatic peripheral facial palsy, recurrent peripheral facial palsy, facial nerve tumors, and peripheral facial palsy in children; and (2) Rehabilitation procedures: surgical decompression of the facial nerve, facial nerve grafting, surgical treatment of long-term peripheral facial palsy, and non-surgical rehabilitation of the facial nerve.

CONCLUSIONS

Peripheral facial palsy is a condition of diverse etiology. Treatment should be individualized according to the cause of facial nerve dysfunction, but the literature presents better evidence-based recommendations for systemic corticosteroid therapy.

A Large Intratemporal Facial Nerve Schwannoma Presenting as an Occluding External Auditory Canal Mass

Facial nerve schwannomas are rare, benign, slow-growing tumors that can occur in any segment of the facial nerve, although 71% of cases are intratemporal. Surgical resection can lead to facial nerve injury. Facial function recovery after reanimation is usually not better than House-Brackmann (HB) grade III. Thus, for cases of intratemporal facial nerve schwannomas (IFNSs) with favorable facial function (HB grade I or II), observation by periodic magnetic resonance imaging is the mainstay of management. Here, we present a case of a large IFNS with normal facial function in which the mass fully occluded the external auditory canal. The occlusion caused squamous debris to accumulate, potentially leading to cholesteatoma. Faced with this therapeutic dilemma, we chose surgical resection with the patient's informed consent. Stripping surgery was achieved with normal postoperative facial function. There was no postoperative facial paralysis or recurrence at 2-year follow-up. We describe the experience of diagnosis and treatment process for this case, and discuss the possibility of total resection of the tumor with preserving the integrity of facial nerve.

Schwannoma in the External Auditory Canal

ABSTRACT

Schwannoma is a slow-growing, benign tumor originating from the Schwann cells of peripheral nerve sheaths. Schwannoma in the external auditory canal is rare but should be included in the possible diagnosis of a cystic mass. If schwannoma is suspected, computed tomography or magnetic resonance imaging should be performed to explore tumor size, location, possible extension, and origin before excision. The authors here present a large schwannoma that almost completely occluded the external auditory canal and was completely excised using a transcanal approach.

Facial nerve schwannoma mimicking chronic suppurative otitis media: A case report

RATIONALE

Facial nerve schwannoma (FNS) is a rare slow-growing nerve sheath tumor derived from Schwann cells. FNS with normal facial nerve function may sometimes be misdiagnosed as otitis media because of similar ontological symptoms such as purulence, tympanic membrane damage, and hearing loss.

PATIENT CONCERNS

A 68-year-old woman was referred to our department because of otorrhea and hearing loss in the right ear for 20 years. Otoscopy revealed abundant purulent secretions deep in the right external auditory canal, and granulation proliferation in the posterior part of membranae tensa. Audiogram showed a right mixed hearing loss with an 85-dB pure-tone average and 35-dB air-bone gap.

DIAGNOSIS

This patient was misdiagnosed as chronic suppurative otitis media before surgery. During surgery, a mass was found, and intraoperative frozen section histopathology confirmed an FNS.

INTERVENTIONS

This patient was subjected to mastoidectomy for curing chronic suppurative otitis media initially. During surgery, a mass was found attached and widely extended into the tympanic and mastoid segments. We removed most part of the mass, however found the mass deriving from the vertical part of the facial nerve. Intraoperative frozen section histopathology confirmed an FNS. So we removed the incurs and malleus, and searched for the edge of the mass. The mass involved multisegments of facial nerve including the tympanic, vertical and pyramidal segments. The tumor was removed completely, and nerves were repaired using greater auricular nerves.

OUTCOMES

After surgery, the patient had facial nerve paralysis of House-Brackmann (HB) Grade VI. Facial function recovered to HB Grade III at 30 months after surgery. The patient was followed up for 5 years. She had a facial function of HB grade III at the most recent follow-up.

LESSONS

FNS is rare and tend to be misdiagnosed. It is important to combine the imaging modalities of computed tomography and magnetic resonance imaging to evaluate FNS before surgery. The primary goal of managing FNS is to maintain normal facial function as long as possible; therefore, tailored strategy should be taken for managing FNS.

Benign Temporomandibular Joint Lesions Presenting as Masses in the External Auditory Canal

OBJECTIVE

Describe benign lesions arising from the temporomandibular joint (TMJ) that presented as masses in the external auditory canal (EAC).

STUDY DESIGN

Retrospective case series of two academic medical centers.

PATIENTS

Six patients with lesions emanating from the TMJ that presented as EAC masses. Lesions included pigmented villonodular synovitis (PVNS), nodular fasciitis, foramen of Huschke herniation with salivary fistula, fibroepithelial polyp, superficial angiomyxoma, and giant cell tumor (GCT).

INTERVENTION

Surgical resection.

MAIN OUTCOME MEASURES

Tumor control, TMJ function, and hearing.

RESULTS

All patients presented with hearing loss, TMJ pain, and otalgia. Three patients with EAC occluding masses developed entrapment cholesteatoma between the mass and tympanic membrane. Following surgical resection, four patients were free of disease. The patient with PVNS has a stable remnant at 3 years follow up and the patient with giant cell tumor is under active surveillance. Hearing improved in three patients, remained stable in one patient, and worsened in two patients. All had resolution of their TMJ and ear pain.

CONCLUSIONS

EAC masses of uncertain origin should be imaged preoperatively to exclude lesions best not biopsied (e.g., encephalocele, facial nerve schwannoma, paraganglioma). In the differential of EAC masses, lesions emanating from the TMJ need to be considered, especially for those based anteriorly. Understanding the extent of TMJ involvement is crucial for surgical planning which optimizes outcome. Goals for therapy are to control the underlying disease process, restore patency of the EAC, improve hearing, and preserve function of TMJ.

Obstruction of the external auditory meatus secondary to a giant pyogenic granuloma

Pyogenic granuloma is a benign lesion of the skin and mucosa commonly known to occur in the head and neck region. The current literature has not yet identified its occurrence within the conchal bowl, a condition that leads to obstruction of the external auditory meatus. We present the case of a 28-year-old man who presented with a history of 3-4 weeks of a rapidly enlarging pedunculated lesion within the conchal bowl of the right ear and conductive hearing loss. Initial management included excision under local anaesthesia. The histological report concluded that it was a pyogenic granuloma. Later, reoccurrence was treated with a more definitive excision under general anaesthesia. During follow-up, the operative site was seen to have healed by secondary intention without reoccurrence. Although a pyogenic granuloma within the conchal bowl is benign, early therapeutic excision is important for histological diagnosis as much as to relieve consequential secondary obstruction and conductive hearing loss.

Primary tumors of the facial nerve

This article describes the pathophysiology, diagnosis, treatment, and outcomes of primary tumors of the facial nerve. These tumors include facial nerve schwannomas, geniculate ganglion hemangiomas, glomus facialis, and granular cell tumors. Although these tumors are rare, collected data help to form a consensus with regard to optimal treatment methods.