Primary and secondary tumors of the facial nerve. A temporal bone study

Of 1400 temporal bones in the collection at the University of Minnesota, Minneapolis, 17 temporal bones from 15 patients were found to have tumors involving the facial nerve. The findings were as follows: one case of facial nerve schwannoma; two cases of invasion of the facial nerve by contiguous tumor; and 14 cases of metastatic tumors involving the facial nerve. Facial nerve paralysis was present in half of the cases (nine of 17). Facial nerve paralysis was present in the case of facial nerve schwannoma, in both cases of invasion of the facial nerve by contiguous tumor, and in six of 14 cases of metastatic tumors involving the facial nerve. The presence of the facial nerve paralysis correlated well with the degree of tumor infiltration into the nerve fibers and the segment of the tumor involvement in the facial nerve. In the patients with metastatic tumors, facial nerve paralysis was a sign of extensive intracranial tumor involvement and was usually accompanied by other cranial nerve palsies, most commonly involving the fifth nerve.     

面神经瘤误诊分析

目的总结分析面神经瘤误诊的原因，提高对面神经瘤的认识。方法1993年1月至2006年9月手术治疗的28例面神经瘤患者，11例有误诊的经历。所有患者均行CT或MRI检查、纯音测听，面神经功能的评估采用House-Brackman（HB）系统。结果11例患者被误诊。2例术前被误诊为腮腺肿块，行腮腺浅叶切除术，术中发现肿块来自面神经。4例单侧面神经麻痹长期外院误诊为贝尔面神经麻痹，病史1至8年。由于长期面神经麻痹无好转，行影像学检查发现面神经占位病变。2例复发性面神经麻痹误诊为贝尔面神经麻痹，行影像学检查发现均为面神经膝状神经节占位。1例因左耳渐进性听力下降，体检见外耳道新生物，诊断为外耳道新生物，行活组织检查示神经鞘瘤，进一步影像学检查提示为面神经瘤。1例右耳流脓数年，面神经麻痹1个月。查体示右鼓膜穿孔，CT检查诊断为慢性中耳炎行手术，术中见上鼓室肿块同面神经关系密切，取部分组织送病理，术后病理为面神经鞘瘤。另1例面神经麻痹1年半，CT检查误诊为先天性胆脂瘤，入院后发现乳突肿块同面神经关系密切，MRI证实为面神经肿瘤并且侵及腮腺内面神经。11例均经手术和病理证实。结论面神经瘤较罕见，不为大多数临床耳科医生熟悉，在临床中易被漏诊和误诊。临床中，如贝尔面神经麻痹半年内无好转现象或患者表现为反复面神经麻痹，应行影像学检查排除面神经瘤的可能。如患者出现面神经麻痹，CT示中耳占位并同面神经关系密切时，行MRI检查可同中耳胆脂瘤、肉芽、胆固醇肉芽肿等区分。腮腺肿块同面神经总干关系密切者应警惕面神经可能。     

Dermoid cyst in the facial nerve--a unique diagnosis

Facial nerve paralysis in children may occur as a complication of infections, trauma, or rarely from benign or malignant tumors of the facial nerve. We present the first reported case of a dermoid tumor in the facial nerve causing facial paralysis in a child. Case report at a tertiary Children's Hospital. A 9-month-old was referred to our institution for evaluation of persistent, complete right sided facial paralysis three months after receiving a diagnosis of Bell's palsy. A workup at our institution including MRI and CT revealed marked widening of the facial canal in the mastoid segment consistent with facial nerve schwannoma or hemangioma. Surgical exploration via mastoidectomy and facial nerve decompression revealed keratinous material containing hair that had fully eroded the facial nerve, disrupting it completely. The entire tumor was removed along with the involved segment of facial nerve, and the missing facial nerve segment was cable grafted. Histological examination of the tumor confirmed a ruptured dermoid cyst in the facial nerve. Facial nerve tumors are rare causes of facial paralysis in children, accounting for fewer than 10% of cases of facial paralysis in the pediatric population. Dermoid cyst can occur throughout the head and neck region in children, but a dermoid tumor in the facial nerve has not been described in the literature prior to this report. This represents a new and uncommon diagnostic entity in the evaluation of facial nerve paralysis in children. Appropriate imaging studies and pathology slides will be reviewed.     

The inflammatory pseudotumor presenting periodic acid-Schiff-positive inclusions with acute unilateral facial nerve palsy

Although most acute peripheral facial palsies can be attributed to Bell’s palsy, other factors, such as infection, trauma, and neoplasm, can cause facial palsy as well. Among these, facial nerve tumors are rare but should be considered in the differential diagnosis of facial palsy. Palsies due to facial nerve tumors usually present with slow onset but occasionally present as acute episodes. In such cases, facial nerve decompression is the treatment of choice to allow the tumor room to grow without compressing the nerve or its blood supply. We describe a case of severe, acute facial palsy presenting with a spindle-shaped bone erosion on the mastoid portion of the facial canal. Although facial neuroma was suspected preoperatively, emergency decompression surgery revealed that an unusual inflammatory pseudotumor was responsible for the finding. Postoperative histological analysis revealed extensive destruction of the nerve fibers, with extensive infiltration of foamy macrophages containing characteristic, diastase-resistant, periodic acid-Schiff (PAS)-positive inclusions, which are hallmark of the uncommon bacterial infections. This was a case of facial palsy with an unusual etiology. The case shows the benefit of decompression surgery not only as treatment for the palsy but also as exploratory surgery in cases of facial nerve tumor.     

Metastatic squamous cell carcinoma in the neck invading the facial canal--a case report

The results of histopathologic examination of the temporal bone of a 71-year-old woman with squamous cell carcinoma of the tonsil and ipsilateral facial palsy are presented. The right temporal bone was directly involved by metastatic spread of the primary lesion to the right upper cervical lymph nodes. Tumor cells had invaded the canal of the facial nerve, the chorda tympani nerve, and the stapedius muscle, as well as the air cells in the mastoid region. However, although tumor cells had infiltrated the facial canal to a considerable distance from the metastatic tumor mass, the facial nerve had not been infiltrated. Slight degeneration of the facial nerve, however, was observed and appeared to have been caused by compression by the tumor.     

Paraganglioma of the facial nerve,a rare differential diagnosis for facial nerve paralysis: case report and review of the literature

This report describes a rare case of histopathologically confirmed glomus faciale tumor. The role of imaging in the differential diagnosis is discussed and therapeutic options are evaluated, along with a review of the previous literature on glomus faciale tumors. A 39-year-old male patient presented with total peripheral facial nerve paralysis. He underwent radical tumor resection and facial nerve grafting for a histopathologically confirmed paraganglioma of the facial nerve. He is now tumor-free after a 4-year follow-up period, and the functional outcome after primary nerve grafting is satisfactory. Facial nerve paragangliomas are a rare cause of facial nerve paralysis. Early imaging using computed tomography and magnetic resonance imaging is essential to clarify the differential diagnosis and assess the location and extent of the tumor. Precise pathological diagnosis requires additional targeted immunohistochemical examinations. The treatment of choice in patients with preoperative facial nerve paralysis is radical tumor resection with nerve reconstruction.     

Facial nerve management in temporal bone hemangiomas.

Eight patients with intratemporal hemangiomas involving the facial nerve are reported to present their symptoms, pathology, surgical management, and results. These unusual tumors have a predilection to involve the facial nerve, usually at the geniculate ganglion, internal auditory canal, or middle ear. Patients presented with facial palsy that was sudden, gradual in onset, recurrent, or associated with hemifacial spasm. Symptoms often progressed for years before the diagnosis was made. In two cases the tumor caused bony remodeling with an expansile honeycombed appearance, but no neoplastic production of bone. The facial nerve was comprised either by tumor compression or nerve invasion, as seen in two of our patients. Complete removal of the tumor and rehabilitation of the facial nerve function was attained in each case. Because of the destructive nature of these benign tumors, intratemporal facial nerve grafting was required in five of the eight cases. Results of facial nerve repair were good except in cases of long-standing facial dysfunction.     

Neurophysiologic intraoperative monitoring: II. Facial nerve function

Intraoperative facial nerve monitoring provides a potentially useful adjunct to recent surgical advances in neurotology and neurosurgery. These measures further aid the surgeon in preserving facial nerve function by enhancing visual identification with electrical monitoring of mechanically evoked facial muscle activation. Facial nerve monitoring in neurotologic surgery may achieve the following goals: (1) early recognition of surgical trauma to the facial nerve, with immediate feedback made available to the surgeon through monitoring of mechanical activation; (2) assistance in distinguishing the facial nerve from regional cranial nerves and from adjacent soft tissue and tumor with selective electrical stimulation; (3) facilitation of tumor excision by electrical mapping of portions of tumor that are remote from the facial nerve; (4) confirmation of nerve stimulability at the completion of surgery; and (5) identification of the site and degree of neural dysfunction in patients undergoing nerve exploration for suspected facial nerve neoplasm or undergoing decompression in acute facial palsy. This paper provides an overview of intraoperative facial nerve monitoring principles and methodology and reports a recent clinical investigation that demonstrates the utility of facial nerve monitoring in translabyrinthine acoustic neuroma surgery.     

Facial nerve neuroma Report of two cases including histological and radiological imaging studies

Unlike the acoustic neuroma, a facial nerve neuroma is an uncommon finding, even in referral clinical centers. Two cases of facial nerve neuromas are presented, with special focus on the importance of adequate radiological imaging techniques and histological characteristics of tumor specimens. Surgical modalities regarding tumor removal as well as facial nerve repair are discussed and the current world literature reviewed.Presented at the February meeting of the Belgian Society of Otorhinolaryngology and Cervicofacial Surgery, 20 February 1993, Brussels, Belgium     

The facial nerve in acoustic tumor surgery

The results of facial nerve function in twenty-four cases of acoustic neuroma removal using translabyrinthine approach from 1982 to 1987 were reported. Facial nerve had been paralysed in one case preoperatively. The facial nerve function were preserved in 21 out of 23 cases (91.3%). The appearance of facial nerve during surgery was as follows: normally located in 9 cases, displaced and deformed in 12 cases and invaded by the tumor in 3 cases. The size and location of the tumor determine the chance of preservation of facial nerve function. The procedures of manipulating the facial nerve and preventing the injury to the facial nerve during surgery were discussed in detail.     

Huge middle ear adenoma with delayed facial nerve paralysis

Middle ear adenoma is a rare disease that arises from the mucosa of the middle ear. Only a few cases of associated facial nerve paralysis have been reported. Facial nerve involvement is most likely related to nerve compression rather than tumor invasion of the nerve. We describe a case of a huge middle ear adenoma in a 63-year-old man. He presented with a 1-month history of right-sided otalgia, otorrhea, and facial palsy; he also had a 10-year history of right-sided hearing loss. A tympanomastoidectomy was performed. Intraoperatively, the tumor was found to fill the middle ear cavity as well as the entire diameter of the external auditory canal. The tumor had eroded the wall of the facial canal at the second genu, and it was tightly adherent to the epineurium. Focal inflammation around the tumor was observed at the exposed facial nerve. The tumor was removed and the facial nerve was decompressed. Immediately after surgery, the patient's aural symptoms resolved. The final pathology evaluation established the diagnosis of a middle ear adenoma. At the 3-year follow-up, the ear cavity was completely healed and facial nerve function was improved.     

An alternative treatment for facial nerve tumors: short-term results of radiotherapy

A review of medical records of patients undergoing radiotherapy for facial nerve tumors was undertaken to determine subsequent facial nerve results, hearing results, and tumor control. Two patients with facial nerve tumors received this treatment. Facial nerve function remains excellent in one patient and significantly improved in the other. Neither tumor demonstrated growth. Current philosophies of facial nerve schwannoma management attempt to balance tumor control with facial nerve function. Radiotherapy for these tumors appears to preserve short-term facial function and may be a viable alternative to surgical management.     

Facial nerve repair techniques in cerebellopontine angle tumor surgery.

This study reviewed the technique and outcome of facial nerve repair in cases of cerebellopontine angle (CPA) tumor that resulted in transection of the facial nerve. Between January 1982 and December 1989, the facial nerve was preserved in over 97.7 percent of 1110 cases of CPA tumor resection. Facial nerve repair was performed in 23 patients. The nerve repair was accomplished with either suture anastomosis or support with microfibrillar collagen. In the cases repaired with sutures, reanastomosis to a proximal facial nerve stump at the brain stem was performed with a single suture, while stabilizing the nerve with a fenestrated suction. Direct facial nerve neurorrhaphy or anastomosis with a greater auricular nerve interposition graft was successful in restoring tone and some degree of voluntary motion in 18 of the 21 patients with follow-up available (86%) and acceptable function (grade IV/VI or better) in 12 of 21 (57%). The degree of recovery of facial function was significantly better in patients without preoperative facial nerve symptoms and patients in whom the tumor did not arise from the facial nerve itself. We conclude that in cases of facial nerve transection in the CPA, good results are obtained by immediately reestablishing anatomic continuity of the nerve with direct reanastomosis or with a greater auricular nerve graft.     

Surgical treatment of recurrent pleomorphic adenoma of the parotid gland

Recurrent pleomorphic adenomas of the parotid gland warrant consideration because of the potential for facial nerve injury occurring with surgical treatment and the risk of malignant conversion. Forty-eight cases of recurrent pleomorphic adenoma treated at the University of Michigan, Ann Arbor, between 1935 and 1975 were retrospectively analyzed. The results of surgical procedures for recurrence were determined with respect to tumor control and resultant facial nerve function. Malignant conversion developed in three (6%) of 48 cases. The results of this study underscore the importance of adequate surgical excision of initial recurrences as well as primary tumors to prevent tumor recidivism. Tumor control rates and facial nerve preservation are enhanced with formal parotidectomy for recurrent tumor when feasible. In cases in which facial nerve identification and dissection is not possible, en bloc total parotidectomy offers effective, though not absolute, control of extensive recurrence.     

原发性面神经肿瘤的诊断与治疗（附14例报告）

目的 总结面神经肿瘤的临床特点，探讨诊断方法和治疗措施。方法 回顾性总结解放军总医院1986年1月－2000年12月间手术治疗，病理证实的14例原发性面神经肿瘤病例的临床表现，诊断和治疗的经验。结果 14例患者中面神经鞘瘤9例，面神经纤维瘤3例，面神经血管瘤2例。面神经肿瘤的首发症状最常见为面瘫（10／14），其次是听力下降（5／14）。最常见体征是面瘫（10／14），其次是鼓室内肿物（5／14），再次是外耳道肿物（4／14）。本组14例面神经肿瘤均经手术切除治疗，手术中保留面神经完整1例，术后随访3年，面神经功能正常。保持部分面神经连续2例，分别随访1年和3．5年，1例面神经功能为Ⅱ级，1例为Ⅲ级。耳大神经移植桥接面神经6例，平均随访4．5年，面神经功能Ⅱ级2例，Ⅲ级3例，Ⅳ级1例。股外侧皮神经移植桥面神经1例，随访6例，面神经功能级Ⅲ级。1例桥小脑角面神经鞘瘤患者，在肿瘤切除术后9个月时行二期面神经－舌下神经吻合，术后随访3年，面神经功能恢复为Ⅱ级。面神经中断者因断端寻找困难而未处理3例，平均随访2．5年（6月－4年），均为完全性面瘫（Ⅵ级）。结论 面神经肿瘤常见首发临床表现为面神经麻痹。一旦考虑为面神经肿瘤，应尽早手术。在切除肿瘤的同时，尽可能保留面神经的连续性或行一期面神经功能重建，若不能行一期面神经功能重建也要尽可能在短期内行二期功能重建手术。     

Intratemporal facial nerve schwannoma: a management dilemma.

OBJECTIVE: To report the findings in patients with facial nerve schwannoma in whom surgery was elected at onset versus patients treated expectantly. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Twenty-four patients with a mean age of 44 years (range, 18-65 yr) were followed for an average of 6 years (range, 1-19 yr). INTERVENTION: Eleven patients underwent complete tumor excision and 13 patients were enrolled in ongoing monitoring only. MAIN OUTCOME MEASURES: Facial nerve function and hearing acuity were noted at the time of initial and last visits. Magnetic resonance imaging was used to determine tumor growth in those individuals treated expectantly and as a means of excluding tumor recurrence/persistence in those treated surgically. RESULTS: Of the 11 patients who underwent tumor removal, the facial nerve was spared in 7. Eight had varying degrees of facial nerve dysfunction initially. In this group (mean follow-up, 8 yr), six patients had unchanged nerve function, four had improved nerve function, and one had worsened. No long-term recurrence was noted. Of the 13 patients followed expectantly, three had facial weakness initially. During the follow-up interval (mean, 5 yr), facial function remained unchanged for eight and worsened in five. During this interval, 4 of the 13 patients demonstrated tumor growth and 3 have recently undergone tumor removal. CONCLUSION: Facial nerve schwannomas are extremely slow growing and frequently present without facial dysfunction. It is possible to surgically remove these tumors while sparing the nerve; as a result, postoperative function is correspondingly better. Finally, the decision on how to treat these patients should be individualized and based on initial facial function, growth rate, surgical experience, and informed patient consent.     

Surgical Findings to Differentiate Between Facial Nerve Schwannoma and Vestibular Schwannoma

Objectives

Facial nerve schwannomas may be misdiagnosed as vestibular schwannomas (VSs) if the tumor is confined to the internal auditory canal (IAC) without involvement the geniculated ganglion or labyrinthine segment of facial nerve. Because facial nerve schwannomas may be misdiagnosed as VSs, we investigated the differences between the two.

Methods

The study included 187 patients with a preoperative diagnosis of VS. Of these, six were diagnosed with facial nerve schwannomas during surgery. We reviewed the preoperative evaluations and surgical findings of facial nerve schwannomas mimicking VSs.

Results

No useful preoperative predictors are available for facial nerve schwannomas mimicking VSs. Facial nerve schwannomas are usually confined to the IAC. After opening the dura of the IAC, a facial nerve schwannoma can be diagnosed after identifying a normal-appearing nerve located lateral to the tumor. When this was the case, we performed facial nerve preservation surgery or decompression.

Conclusion

Facial nerve schwannomas can be differentiated from VSs by identifying specific findings during surgery.     

Primary paraganglioma in the facial nerve canal

Objective

To describe primary paraganglioma in the facial nerve canal and discuss the characteristics of facial nerve paraganglioma in contrast with other tumors.

Case report

A 23-year-old man developed gradually progressive right facial palsy as the initial symptom. One year later, he exhibited hearing loss without tinnitus in his right ear. CT demonstrated an enlarged facial nerve canal with irregular bony erosion of the circumference. MRI showed a well-enhanced heterogeneous mass with hypo-intensity spots inside it. During surgery, a blood-rich tumor was observed along the facial nerve: however, extensive bleeding interfered with tumor removal. The surgical specimen demonstrated paraganglioma. The tumor was completely removed in the second surgery in combination with arterial embolization. Facial nerve function was reconstructed with a free muscle flap more than one year following resection.

Conclusion

Because paraganglioma is a blood-rich tumor, it is important to perform angiography and embolization. If preoperative facial nerve palsy is demonstrated, careful management of facial nerve function is needed. Paraganglioma must be considered in the differential diagnosis of a facial nerve tumor.     

原发性面神经肿瘤的临床分析

目的分析原发性面神经肿瘤的临床特征，提高对原发于面神经的肿瘤诊断和治疗的认识。方法回顾性分析资料完整、病理诊断明确的10例面神经瘤患者的临床资料。面神经功能评估采用House—Brackmann分级。结果首发症状以面神经麻痹发病并进行性加重7例；以耳部流脓8年、耳后肿痛伴面神经麻痹2周急症入院1例；单纯面部肿物1例；以耳下肿物10年、肿物肿胀剧痛伴面神经麻痹入院1例。7例患者行CT检查，5例同时行MRI检查，6例通过影像学检查发现肿物位于面神经不同部位。4例MRI检查均表现以长T1长1、2信号为主的不均匀信号影，1例MRI无明显阳性征象发现。2例表现为面部或腮腺部位肿物的患者B超显示为病变区的实性占位。患者均行手术治疗，9例患者完全切除肿瘤，无复发，1例部分切除肿瘤；完整剔除肿瘤和部分切除肿瘤各1例，术后面神经功能无变化；完整切除保留部分面神经纤维2例，面神经功能均改善，行面神经修复4例，失败1例，改善3例。结论面神经瘤可累及面神经的多个部位，临床表现以进行性面神经麻痹多见；对于面神经肿瘤的治疗应该考虑到面神经的功能、生长的速度、手术的经验和患者的意愿等因素综合判断；更为有效的治疗方法还需要积极探索。     

Multicentricity of intraparotid facial nerve schwannomas

Facial nerve schwannomas are uncommon neoplasms. Multiple schwannomas of the facial nerve in the parotid region are rare. Research regarding the pathogenesis of multiple facial nerve schwannomas is incomplete. Both the neoplastic bridging of tumor cells and tumor multicentricity have been hypothesized. We present a case of multiple intraparotid facial nerve schwannomas. In this case, the histologic features of the tumors support the multicentric hypothesis.