Schwannoma of the external auditory canal: An exceptional site

IntroductionSchwannomas are benign solitary neural tumours that are only exceptional located in the external auditory canal, as only a few cases have been reported in the literature.Case reportWe report a case of schwannoma of the external auditory canal in an 18-year-old man admitted for an isolated mass of the initial segment of the right external auditory canal visible to the naked eye, obstructing all of the external auditory meatus. Computed tomography of the temporal bone showed an isolated mass of the external auditory canal. Management of this patient consisted of biopsy-excision of the mass, histological examination of which confirmed a schwannoma of the external auditory canal.DiscussionAlthough rare, the possibility of a nerve tumour of the external auditory canal should always be considered. These tumours may be isolated or may occur in the context of von Recklinghausen's disease. The clinical presentation in the external auditory canal may correspond to recurrent otitis externa secondary to obstruction of the canal by the tumour, as in the case reported here. The definitive diagnosis must be based on the results of histological and immunohistochemical examination.     

Schwannoma of the external auditory canal

Schwannomas are uncommon tumors of the external auditory canal. In the English literature, very few cases of schwannomas originating in the external auditory canal were reported. In this report, we described a 44-year-old patient who presented with external auditory canal mass which was managed by local excision. The clinical and histologic features, the differential diagnosis, and the treatment of external auditory canal schwannoma is discussed.     

Schwannoma of external auditory canal

Schwannomas of the external auditory canal are extremely rare and only a few cases have been reported in the literature. Herein, we report a case of schwannoma of the external ear canal in a 41-year male. Clinicians should consider the possibility that the schwannoma may originate in the external auditory canal mimicking other more frequently observed lesions.     

Meningioma in the internal auditory canal

A case is presented of an entirely intracanalicular meningioma in a 48-year-old woman that was excised via a conventional translabyrinthine approach to the internal auditory canal (IAC). Pre-operative magnetic resonance imaging (MRI) suggested that the tumour was a vestibular schwannoma (VS). Histological examination confirmed the intra-operative impression that the tumour was a meningioma. Although VS is by far the commonest intracanalicular tumour, the differential diagnosis includes meningioma. MRI is unable to distinguish between these two entities when the tumour is located entirely in the internal auditory canal.     

Osteoma of the ear canal presenting with headache

Osteoma of external auditory canal is a rare benign tumour. Usually it is found incidentally and often symptomless. Here we have a case of osteoma arising from the anterior wall of the bony external auditory canal, causing ipsilateral temporal headache which was relieved by removal of tumour.     

Magnetic resonance imaging of pleomorphic adenoma arising from the external auditory canal

Pleomorphic adenoma arising from the external auditory canal is a very rare neoplasm, and there has been no report on magnetic resonance (MR) imaging of pleomorphic adenoma of the external auditory canal. We report here a case of 65-year-old male with this tumour, measuring 12 mm in a diameter. Histopathology was confirmed from the specimen obtained at the surgical excision. MR revealed that the tumour had a well-defined margin showing hypointensity on T1-weighted images and hyperintensity on T2-weighted images relative to the parotid gland. The tumour was well enhanced by contrast material. No invasion to the surrounding tissue was observed. These MR findings were compatible with pleomorphic adenoma of the salivary gland origin. In treating pleomorphic adenoma of the external auditory canal, complete surgical excision is essential for the prevention of recurrence. It can be concluded that MR imaging is helpful for making a differential diagnosis of external auditory canal tumours and selection of adequate treatment.     

Acoustic schwannoma presenting as a tumor of the external auditory canal. Case report

An acoustic neurinoma involving the internal auditory canal, the vestibule, the cochlea, the middle ear, and extending into the cerebellopontine angle and the external auditory canal, is described in a 56-year-old woman. An initial episode of vertigo was followed by a 27-year history of progressive unilateral hearing loss leading to complete deafness and areflexia with central compensation. The tumor was removed by a two-step surgical procedure, and the histologic features were those of a schwannoma.     

Schwannoma of the tympanic membrane

Schwannoma arising from the tympanic membrane is a rare neoplasm. This report describes an external ear canal mass obscuring the tympanic membrane. A transcanal approach identified a tumour adhered to the tympanic membrane. The tumour was excised without myringoplasty. Pathology confirmed the diagnosis of schwannoma. Clinical examination revealed no evidence of recurrence during a follow-up period of one year. The possible origins of schwannoma of the tympanic membrane and lesion management are also discussed.     

Primary pleomorphic adenoma (chondroid syringoma) of the external auditory canal. Case report and literature review

Chondroid syringoma of the external auditory canal is an extremely rare neoplasm, representing the cutaneous counterpart of pleomorphic adenoma of salivary glands. This tumour is thought to derive from the apocrine duct of the folliculo-sebaceous-apocrine unit. We report the case of a 68-year-old male in whom the clinical and radiological examinations showed a well-circumscribed tumour limited to the external auditory canal. The diagnosis was confirmed by histologic examination. We also reviewed the literature.     

Drilling and control of the internal auditory canal by fixed endoscope

Preservation of vestibular structures, particularly the posterior semicircular canal, is essential to ensure hearing preservation in addition to complete tumour resection during retrosigmoid surgical resection of a vestibular schwannoma. Drilling of the internal auditory canal (IAC) is a delicate step, during which these structures can be accidentally perforated. The orientation of the IAC results in the formation of poorly visible zones that can predispose to perforation of these structures when drilling is performed with a microscope. Hand-held endoscopy exposes all of the operative field, but immobilizes one of the surgeon's hands, making this surgery even more delicate. Fixed endoscopy is a solution that gives the surgeon greater freedom of movement, while ensuring precise control of the surgical procedure. It allows identification and avoidance of vestibular structures, while allowing resection as close as possible to the tumour. The schwannoma can be entirely cleaved when the fundus of the IAC is correctly controlled, while sparing the facial and cochlear nerves.     

Cochlear schwannoma removed through the external auditory canal by a transcanal exclusive endoscopic technique

Surgical approaches to the inner ear and internal auditory canal (IAC) are widely known and extensively recorded. The most popular can be classified as retrosigmoid, transmastoid‐translabyrinthine, and middle cranial fossa approaches. For the first time, an exclusive endoscopic approach to the IAC is described here, used to remove a cochlear schwannoma involving both the IAC and labyrinth. The operation provided a direct transcochlear intradural approach from lateral to medial and from external to internal auditory canal, without any external incision. The pathology was totally removed, and the postoperative outcome of the facial nerve was grade II (House‐Brackmann grading system) at 3‐month follow‐up. Laryngoscope, 123:2862–2867, 2013     

Postoperative magnetic resonance imaging findings after transtemporal and translabyrinthine vestibular schwannoma resection

OBJECTIVES/HYPOTHESIS: Magnetic resonance imaging (MRI) has become the investigation of choice to follow up patients after vestibular schwannoma resection. STUDY DESIGN: Retrospective. METHODS: Postoperative MRI findings of 70 patients after vestibular schwannoma resection through a transtemporal (n = 48) and a translabyrinthine (n = 22) approach were reviewed. Time-dependent changes in intensity, size, and shape of enhancement in the internal auditory canal before and after contrast administration, postoperative temporal lobe gliosis, and changes of fat grafts were evaluated. RESULTS: After vestibular schwannoma resection, all patients showed signal enhancements in the internal auditory canal ranging from a faint to high signal intensity in the first postoperative MRI, 3 to 6 months after surgery. In the next MRI at 12 to 24 months after surgery, 30 patients (43%) showed a decreased signal, 35 patients (50%) a stable enhancement, and 5 patients (7%) an increased enhancement in the internal auditory canal depicted as an intense nodular or mass-like pattern. In patients with decreased or stable enhancement, a residual tumor could be excluded in the following MRI scans, whereas in all patients with increased enhancements after 12 to 24 months, signal enhancement further increased and residual tumors were detected. Different degrees of temporal lobe gliosis were found in 15 of 48 cases (31%) after transtemporal tumor removal. Enhancement of fat grafts used in 22 cases decreased to different degrees in 14 cases (64%). CONCLUSIONS: Differentiation of residual tumor from scar tissue in the internal auditory canal after vestibular schwannoma resection requires close, long-term follow-up. Nodular and progressive enhancements in the internal auditory canal indicate residual tumor. Linear enhancement in the internal auditory canal has been found to be a common finding after vestibular schwannoma resection not associated with residual tumor.     

Combined surgical approach to intralabyrinthine schwannoma

IntroductionIntralabyrinthine schwannoma (ILS) is a tumor originating from the Schwann cells in the inner ear. Various surgical approaches can be used for the resection of ILS. The aim of this report is to describe a case involving a 60-year-old man who was treated successfully with a combined surgical approach.Case reportThe patient underwent a combined microscopic (transmastoid labyrinthectomy) and endoscopic procedure for surgical excision of ILS involving the vestibule and the lower half of the cochlear basal turn. The combined surgical technique enabled a complete removal of the ILS without removal of the unaffected cochlea as well as the external auditory canal. Besides additional exclusion of the middle ear, blind-sac closure of the external auditory canal and cavity obliteration were avoided. No postoperative complications were observed.DiscussionA combined microscopic and endoscopic approach to surgery enables removal of the ILS involving the vestibule and the lower half of the cochlear basal turn while helping to reduce surgical radicality.     

Paraganglioma of the external auditory canal: an unusual case

Primary paraganglioma of the external auditory canal is a rare otological finding. To date, only three cases have been reported in the world-wide literature. Such a tumour is now described in a 42-year-old female. The clinical and histopathological features of the case are discussed. The role of immunocytochemistry in defining diagnosis, from a large list of differentials, is illustrated. We present the first magnetic resonance images of this rare tumour and highlight the benefit of intra-operative frozen section in limiting surgery to canal excision.     

Carcinoma of the external ear canal and middle ear as interdisciplinary challenge for ear surgery and radiotherapy

BACKGROUND: Carcinoma of the external auditory canal are tumours considered to have a poor prognosis. Improvement of the survival rate by surgical means alone is not possible. Individual therapy modalities as a result of an interdisciplinary approach between otosurgeon and radiotherapist are necessary. PATIENTS AND METHODS: A series of 30 patients (3 patients pretreated at other institutions) with carcinoma of the external auditory canal and middle ear treated between 1978 and 1997 in our institutions was analysed with particular reference to tumour size and its relation to surrounding tissues, patterns of neck node involvement, surgical procedures, and radiation techniques. Clinical endpoints were freedom from local failure, overall survival, disease-free survival. The mean follow-up was 4.7 years (range: 0.1 to 18.8 years), median 3 years. RESULTS: Treatment by surgery and radiotherapy resulted in an overall 5-year survival rate of 51%. According to Pittsburgh classification the 5-year survival rate for early disease (T1- and T2-tumours) was 89%, for stage III 67% and for stage IV 39%. Most important prognostic factors were dural infiltration (all patients with dural invasion died within 2.2 years) and the infiltration of surgical margins (the 5-year survival rate of patients with complete tumour resection was 100%, but 54% in patients with tumour beyond surgical margins). 192-iridium HDR afterloading brachytherapy based on 3D CT-treatment planning is an effective tool in the management of local recurrences following surgery and a full course of external beam radiotherapy. CONCLUSIONS: Surgical resection followed by radiotherapy adapted to the stage of disease and grade of resection is the preferred treatment of cancer of the external auditory canal and middle ear.     

Acquired external auditory canal stenosis: assessment and management

PURPOSE OF REVIEW: Although uncommon, acquired external auditory canal stenosis is an entity that is encountered by many otolaryngologists. This paper reviews the causes, pathogenesis, assessment, and management options for external auditory canal stenosis. RECENT FINDINGS: Initially, acquired external auditory canal stenosis was described as resulting from a number of different causes. Since then, histology and imaging studies of this disease have shown that a common cascade of inflammatory changes resulting from these different causes is the primary pathogenesis leading to medial canal fibrosis. Once there is complete obstruction of the external auditory canal, surgery is the primary treatment. Understanding the strong role of inflammation in the pathogenesis of external auditory canal stenosis may lead to new preventative medical therapies. SUMMARY: Although acquired external auditory canal was described several years ago, its underlying pathophysiology is now better understood. From this knowledge, improved medical as well as surgical approaches can be developed.     

Myxoma of the external auditory meatus

A case of myxoma of the external auditory meatus is described. The patient presented with a recurring tumour which had not been correctly diagnosed although the growth had been removed ten times over a period of two years. The tumour was skin covered, contained gelatinous material and was attached to the tympanic membrane and anterior canal wall. Following recognition of the tumour as myxoma, removal was performed with sufficiently wide margins and there has been no recurrence during follow-up for one year.     

A purely intracanalicular cochlear schwannoma presenting with progressive hearing loss

Schwannomas arising from the cochlear nerve and confined to the internal auditory canal are rare. Clinically, a cochlear schwannoma can cause a progressive hearing loss. We report the case of a 56-year-old woman with a cochlear schwannoma that manifested as a slowly progressive hearing loss. The lesion was diagnosed by gadolinium-enhanced 3-Tesla magnetic resonance imaging.     

A case of osteoma with cholesteatoma in the external auditory canal

Osteoma in the external auditory canal (EAC) is an uncommon benign lesion, which presents as a solitary, unilateral, and slow-growing pedunculated mass in the outer half of the bony canal. It is usually asymptomatic; but symptoms can arise if a canal obstruction occurs. External canal cholesteatoma is also a rare lesion of the external auditory canal. Cholesteatoma of the external auditory canal may arise via several mechanisms. However, an occlusion or narrowing of the external auditory canal is the basic pathogenesis. The association of an osteoma with a cholesteatoma is extremely rare, and there have been very few reports published. We encountered a rare case of a 49-year-old man with an osteoid osteoma that was complicated by a cholesteatoma in the external auditory canal. The canal wall down mastoidectomy and tympanoplasty successfully removed the osteoma and the cholesteatoma, and no recurrence or complications had occurred in the first 6 months postoperatively.     

Ectopic extra-cranial meningioma presenting as an aural polyp

Ectopic meningiomas located within the external auditory canal without any intracranial connection are an extremely rare finding. A report is made of a 38-year-old woman presenting with a conductive hearing loss due to an aural polyp, which was subsequently diagnosed as a meningioma. Computer-aided tomography (CT) and magnetic resonance imaging (MRI) showed the tumour to be entirely extracranial. Complete tumour excision was achieved using a modified radical mastoidectomy approach.