Diagnosis and management of intralabyrinthine schwannomas.

OBJECTIVES/HYPOTHESIS: Describe the symptoms, signs, radiographic findings, and treatment results for four patients with intralabyrinthine schwannoma beginning either primarily within the labyrinth or extending secondarily into the labyrinth from the internal auditory canal. STUDY DESIGN: Retrospective review. METHODS: Review of clinic records, operative records, imaging studies with follow-up telephone interview, and when possible, repeat examination. RESULTS: Four patients with intralabyrinthine schwannoma treated by the first author were identified. Episodic vertigo, indistinguishable from Meniere's disease, was present in all but one of the patients in this study. A progressive unilateral hearing loss was also found in all of the patients. Magnetic resonance imaging revealed tumor isolated to the vestibule in two patients with the cochlea primarily involved in the other two patients. Intracochlear tumor extending into the internal auditory canal had been missed on preoperative imaging in one patient and was found during a translabyrinthine vestibular nerve section. In another patient with an intracanalicular schwannoma, tumor extending into the basal turn of the cochlea was not removed during a translabyrinthine approach to the internal auditory canal. The tumor subsequently recurred, necessitating a transotic approach for removal. A transmastoid/translabyrinthine approach was used to successfully remove tumor in one patient. Another patient with good hearing and no vestibular symptoms at time of this writing is being followed with serial imaging studies. As expected, the three patients who underwent surgery have anacusis in the operated ear and are free of vertigo at follow-up intervals of 12, 26, and 65 months. CONCLUSIONS: Intralabyrinthine schwannomas are rare tumors with optimal treatment being determined by the symptoms, tumor location, and hearing. Findings of an intralabyrinthine schwannoma on magnetic resonance imaging may be easily overlooked and attributed to inflammatory changes.     

Histopathology of 30 non-operated acoustic schwannomas

Summary Thirty of 1720 temporal bones from the Wittmaack's Collection contain nonoperated acoustic neuromas, 22 of them large tumors. Histologically, each tumor has to be considered as an individual. Most of the tumors show a mixture of Antoni type A and B. Tumor vascularization is pronounced in half the cases. Vessels of the internal acoustic meatus are found in all cases. Protein contents of the perilymphatic spaces is medium to pronounced in 23 of 30 cases in comparison to the small protein contents of the healthy side.Ganglion geniculi is invaded in 11 cases (9 von Recklinghausen's disease), Ganglion Scarpae in 26 cases (9 von Recklinghausen's disease), and Ganglion spirale in 9 cases (7 von Recklinghausen's disease).Cochlear and vestibular nerve fibers within the internal auditory meatus were affected by the tumor in 28 of 30 cases, the facial nerve only in 11 cases, among them 9 cases of von Recklinghausen's disease.Twenty-six of 30 schwannomas have a portion within the cribriform area of the cochlea fundus, which explains the limitation to radical tumor surgery without damage of the cochlear nerve. These histological findings explain the site of damage of hearing to expand between the cochlea to the auditory brain stem nuclei, and support the audiological experience that a correlation of acoustic neuroma and retrocochlear lesion is often not correct.Paper presented at the Seminar on Diagnosis and Management of Acoustic Neuromas and Skull Base Tumors, Los Angeles, February 1978. Dedicated to Professor Dr. George Keleman on the occasion of his 88th birthday     

Management of intralabyrinthine schwannomas

OBJECTIVES: Our protocol to manage the intralabyrinthine schwannoma (ILS). METHODS: Retrospective chart review of 7 consecutive patients managed for ILS. RESULTS: Five patients underwent surgical removal of the lesions and none experienced significant complications or recurrent disease. One patient refused surgical treatment and was closely followed by serial MRI scans with no signs of tumor growth. One patient is presently managed conservatively due to a good hearing. CONCLUSIONS: Diagnosis of ILS is based on high resolution MRI scans and should be included in the differential diagnosis of patients investigated for cochleovestibular symptoms. Treatment modality of ILS is controversial and depends patients' age, severity of vertigo and hearing loss. In the authors' experience surgery is indicated in all cases with invalidating vertigo and in the young patients with severe hearing loss. Conservative strategy is advised in older patients and in cases with preserved good hearing and no invalidating vertigo. These patients must be followed up using high resolution MRI because of the risk of tumor growth into the internal auditory canal. While tumors with exclusive involvement of the inner ear may be removed by means of a completely extradural approach, tumor growth with involvement of the internal auditory canal dictates the necessity of opening the dura exposing the patients to the potential risks associated with the procedure.     

Atypical sinonasal Schwannomas: A difficult diagnostic challenge

Objective

Schwannomas are benign tumours arising from Schwann cells of the peripheral nerve sheath. They are relatively frequent in the head and neck region (25–45%) but rarely involve in the sinonasal tract (4%). The authors outline the diagnostic difficulties and the problems in choosing the best surgical approach in two atypical cases of sinonasal Schwannomas.

Methods

In the first case reported clinical data, sex and age of the patient, nasal endoscopy and angio-MRI led us to suspect an angiofibroma; therefore, we approached the case without a biopsy performing a preoperative selective embolization followed by an endoscopic resection. In the second case, due to initial visual symptoms and to the ethmoid-orbital compartment involvement, we performed a sinonasal endoscopy and collected a biopsy which resulted to be fundamental in the diagnostic assessment. Tumour excision was then obtained throughout an intracranial/endonasal approach.

Results

The two presented cases revealed the presence of cystic Schwannomas. In the first case, diagnosis was made only post-operatively after histological examination. Patients underwent complete surgical excision by means of an endoscopic sinonasal approach, in the second case associated to a left frontal craniotomy. The patients showed no signs of recurrence at a 9 months follow-up.

Conclusions

Nasal endoscopy was extremely important in making the diagnosis, allowing an accurate assessment of the tumour extension and a biopsy. The diagnosis of sinonasal Schwannomas remains challenging; sometimes, clinical behaviour and modern imaging may be misleading. The diagnostic and therapeutic importance of sinonasal endoscopy is emphasised in the two presented cases.     

Intracochlear schwannoma: Imaging diagnosis

Intralabyrinthine schwannomas (ILS) are rare benign tumors, often responsible for hearing loss. MRI is important in establishing the diagnosis. We present the example of a 48-year-old lady who reported a 3-years history of right-sided sensorineural deafness. MRI demonstrated a loss of the normal hypersignal of the second turn of the right cochlea compatible with intracochlear schwannoma.     

Jugular foramen schwannomas: diagnosis, management, and outcomes

OBJECTIVES/HYPOTHESIS: To describe the presentation, radiographic findings, and surgical management of seven patients who have been diagnosed and treated with jugular foramen schwannomas at the University of Utah. STUDY DESIGN: Retrospective chart review. METHODS: The charts of seven patients diagnosed with jugular foramen schwannomas were reviewed for presentation symptoms, radiographic findings, and physical examination findings. For the six who underwent surgical excision, the surgical procedure used, cranial nerve function results, audiometric results, perioperative complications, and other follow-up data are presented. RESULTS: Seven patients were identified from ages 24 to 69 years. Six of the seven underwent surgical excision. Primary presentation symptoms included dizziness, hearing loss, dysphagia, diplopia, tongue paresis, and hoarseness. The choice of surgical approach was based on the size and location of the tumor. All patients had complete excision of their tumors. The nerve of origin included the glossopharyngeal, vagus, and spinal accessory nerves. Preoperative cranial nerve dysfunction continued postoperatively for lower cranial nerves but resolved in patients who were noted to have preoperative dysfunction of cranial nerve V and VI. The rate of new lower cranial nerve injury was 15% and was only seen in the cranial nerves that were determined to be the nerve of origin. In two cases, a temporary feeding tube was required. No recurrences have been noted to date. CONCLUSIONS: Jugular foramen schwannomas can be successfully diagnosed preoperatively with computed tomography and magnetic resonance imaging. These tumors can be successfully managed with surgery and low morbidity.     

Non-vestibular head and neck schwannomas: a 10-year experience

Schwannomas are rare and slow growing tumours, arising from Schwann cells which provide myelin; less than 1 % of them degenerate into a malignant state. Although most studies are based on acoustic schwannomas, the majority of these tumours are non-vestibular and extracranial. Up to 45 % of them can be localised in head and neck districts, where they represent a diagnostic challenge because they are in differential diagnosis with lipoma, brachial cyst, paraganglioma and adenopathy. Between February 2002 and September 2012 our experience considers 18 patients affected by schwannomas localised in the neck in 14 cases, in the oral cavity in 2 cases, in the upper lip in 1 case and finally in the nose in 1 case. A painless neck mass was the major symptom referred, as well as dysphonia and oral pain. Ultrasound scan with fine needle aspiration biopsy was done in half of the group and was diagnostic in 30 %, whereas magnetic resonance imaging was diagnostic in 77 %, confirming its primary role in diagnostic work-up. The surgical approach was mainly by cervical incision and the intraneural extracapsular enucleation was the technique used without nerve injury in 89 % of cases. Follow-up period was 6–120 months and no evidence of relapse was registered.     

Neck nerve trunks schwannomas: clinical features and postoperative neurologic outcome

Objectives/Hypothesis: To analyze clinical and epidemiological features of neck nerve schwannomas, with emphasis on the neurologic outcome after surgical excision sparing as much of nerve fibers as possible with enucleation technique. Study Design: Retrospective study. Methods: Review of medical records from 1987 to 2006 of patients with neck nerve schwannomas, treated in a single institution. Results: Twenty-two patients were identified. Gender distribution was equal and age ranged from 15 to 61 years (mean: 38.6 years). Seven vagal, four brachial plexus, four sympathetic trunk, three cervical plexus, and two lesions on other sites could be identified. Most common symptom was neck mass. Local or irradiated pain also occurred in five cases. Median growing rate of tumors was 3 mm per year. Nerve paralysis was noted twice (a vagal schwannoma and a hypoglossal paralysis compressed by a vagal schwannoma). Different techniques were employed, and seven out of nine patients kept their nerve function (78%) after enucleation. No recurrence was observed in follow-up. Conclusions: Schwannomas should be treated surgically because of its growing potential, leading to local and neural compression symptoms. When possible, enucleation, which was employed in 10 patients of this series, is the recommended surgical option, allowing neural function preservation or restoration in most instances. This is especially important in the head and neck, where denervation may have a significant impact on the quality of life.     

Conservative management of vestibular schwannomas: an effective strategy

Objectives: Stimulated by the availability of a larger sample of patients and a longer follow‐up period, we update our experience with conservative management of vestibular schwannomas. Study Design: Patients with intracanalicular and small/medium‐sized tumors have been followed prospectively at a tertiary referral center. Methods: One hundred twenty‐three patients affected by sporadic vestibular schwannoma were primarily observed by means of magnetic resonance imaging scans. In case of significant tumor growth (≥2 mm), patients were either surgically treated or submitted to radiotherapy, but, not rarely, they continued to follow the “wait‐and‐scan” policy. Tumor‐size changes over time were also evaluated with hearing function. Statistical analysis with predictive growth factors was performed. Results: Almost two thirds (64.5%) of the cases did not show tumor growth during the entire period of observation (mean follow‐up period, 4.8 yrs). Among growing tumors, 16 patients were surgically treated with no complications or facial nerve palsy. Less than half (45.5%) of the patients presented useful hearing (classes A and B of the American Academy of Otolaryngology–Head and Neck Surgery classification) at diagnosis, and 41 (73.2%) patients had preserved hearing during follow‐up independently from the tumor growth rate. Conclusions: Conservative management of vestibular schwannoma appears to be a safe procedure because most tumors do not grow and surgical outcomes are not affected by possible delays. In the great majority of cases, useful hearing is maintained over time. Because of the irregular behavior of the tumor, periodic neuroradiologic scans are mandatory to limit late surgical risks.     

Extracranial head and neck schwannomas: a clinical analysis of 33 patients

OBJECTIVE: To study the clinical features, diagnosis, and management of the extracranial head and neck schwannomas. STUDY DESIGN: Retrospective study. METHODS: The clinical data of 33 patients with schwannoma of the head and neck from 1996 to 2006 were studied retrospectively. RESULTS: Extracranial head and neck schwannomas usually presented as solitary and well-demarcated lesions with insidious course. Although benign, the lesion can cause secondary symptoms, such as nasal obstruction, dysphasia, and hoarseness, relevant to location of the lesion. Fine needle aspiration cytology, computed tomography scans, and magnetic resonance imaging may provide limited implications in the diagnosis of schwannomas, whereas postoperative pathologic examination establishes the final diagnosis. CONCLUSIONS: Complete surgical excisions with appropriate approaches have proven to be efficient and successful in the treatment of head and neck schwannomas.     

Extracranial head and neck schwannomas: a review of 8 years experience

Schwannomas of the head and neck are uncommon tumors that arise from cranial, peripheral or autonomic nerves. In this study we review a series of 52 cases of schwannoma originating in the head and neck region over an 8-year period. All the tumors were benign, with the exception of one malignant schwannoma. The age range of the patients studied was 13-76 years and there was a predilection for males. Twenty-five schwannomas occurred in the scalp, face and external ear canal, 9 in the oral or nasal cavity and 18 in the neck. Seven cases of neck schwannoma originating from the major nerve system were found in the parapharyngeal space, all of which were located in the post-styloid compartment. Cervical plexus schwannomas originated either in the peripheral nerves or in an unidentified area of the nervous system; seven tumors were found in the posterior triangle of the neck and two in the anterior triangle. Two of the tumors originating in the brachial plexus were located in the posterior neck and one in the anterior neck. Tumors originating in the vagus nerve or sympathetic chain were all located in the anterior triangle of the neck.