Primary middle ear schwannoma

Schwannomas of the middle ear may originate from the nerves of the middle ear cavity or by extensions from neighboring structures. We present a case of a 51-year-old female patient with primary middle ear schwannoma believed to arise from Jacobson's nerve. The tumor was easily divided from the facial nerve and the chorda tympani nerve. Erosion of the promontory was noted, and the jugular foramen and posterior wall of the ear canal were preserved without destruction. The mass was successfully removed by a canal down mastoidectomy procedure, while preserving the hearing and facial nerve functions of the patient. To our knowledge, this is only the second reported case of a patient with Jacobson's nerve schwannoma.     

Impact of Jacobson's (tympanic) nerve sectioning on middle ear functions.

OBJECTIVE: The purpose of this study was to evaluate the influence of sectioning of the Jacobson's (tympanic) nerve on middle ear functions. METHOD: Twenty-five adult New Zealand rabbits were included in this study. The Jacobson's nerve was cut in the left ear of the rabbits (study group), whereas only a small mucosal incision was performed while keeping the Jacobson's nerve intact in their right ear (control group). After the operation, the ears were assessed both otomicroscopically and histopathologically on Days 30, 60, and 90. RESULTS: On otomicroscopy, retraction pockets were observed in 48 and 4% of the ears in the study and control groups, respectively (p < 0.001). Middle ear effusion was observed in 56 and 12%, respectively (p < 0.01). Histopathologically, an inflammation in the middle ear mucosa was present in all ears in the study group, whereas it was present only in 20% of the control ears (p < 0.001). Goblet cells were observed in 48 and 20% in the study and control groups, respectively (p < 0.04). In the study group, the otomicroscopic and histopathologic findings were more prominent on Day 60 compared to Day 90 (p < 0.05). CONCLUSION: Tympanic glomus cells seem to act as middle ear chemosensory organs and are involved in the regulation of middle ear aeration. Disruption of these neural elements such as Jacobson's nerve negatively impacts on middle ear functions and may result in atelectasis.     

Middle ear adenoma with neuroendocrine differentiation (MEA-ND) in the pediatric population

Middle ear adenoma with neuroendocrine differentiation is an uncommon tumor of the tympanic cavity. The terminology of this entity has suffered due to a poor understanding of the differentiation of these neoplasms, and has included both “adenoma” as well as “carcinoid tumor.” Immunohistochemical techniques have helped clarify that these tumors all share elements of neuroendocrine differentiation. Occurrences of this tumor in the pediatric population are extremely rare. In the world literature, only three pediatric cases of middle ear adenoma with neuroendocrine differentiation have been described. We report the youngest case to date of middle ear adenoma with neuroendocrine differentiation, in a 13-year-old boy. We discuss the differential diagnosis, surgical management, and pathology of this entity.     

Carcinoid of the middle ear: a rare tumor with biphasic differentiation. Case report with special reference to immunohistochemistry and electron microscopy]

Progressive unilateral sensorineural deafness and tinnitus developed in a 59-year-old woman over a 1-year period. Clinical examination showed a tumor mass which almost completely filled the tympanic cavity, and grew around the auditory ossicular chain. Histological findings revealed the tumor to be a primary carcinoid of the middle ear. Neuro-endocrine differentiation was confirmed immunohistochemically by positivity for neuron-specific enolase, chromogranin, pancreatic polypeptide and synaptophysin. Using electron microscopy, neuroendocrine granules could be visualized. In addition, both light and electron microscopy revealed that cells had an epithelial differentiation with mucin granules while immunohistochemistry showed a positivity for cytokeratins. The detection of intermediary filaments (immunohistochemically with vimentin and under electron microscopy) was unique to this neoplasm and has to be considered in distinguishing the carcinoid tumor from the papillary adenoma of the middle ear. Tumor prognosis is excellent with radical extirpation from the middle ear. In the case presented, there has been no evidence for either recurrence or metastases 10 months after surgical resection.     

Effectiveness of the CO2 laser in experimental tympanic neurectomy

As one of a series of investigations to evaluate the efficacy and safety of CO2 lasers in otologic microsurgery, squirrel monkeys were subjected to tympanic neurectomies by means of vaporizing Jacobson's nerve in the promontory region. Air and bone conduction hearing acuity was measured by computer-averaged pure tone evoked responses and behavioral audiometry before and after laser surgery. A moderate (avoidable) conductive loss was found as a consequence of the surgical approach selected, but no significant sensorineural loss was apparent. Thus, there would appear to be no adverse cochlear side effects as a result of using this instrument in the middle ear. The laser neurectomy procedure, however, was no more effective for the clinical purposes for which it was proposed than those techniques reported by several other investigators.     

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.     

Use of autograft and homograft TORP and PORP in the reconstruction of the conductive system in the middle ear

The restoration of a functional transmission system of the middle ear is extremely difficult after a radical operation which leaves a large surgical cavity or in the absence of the tympanic membrane and ossicles, when the window and the tympanic ostium of the tube are covered with thick granulation and fibrous tissue. This article describes my experience in restoring the transmission system of the middle ear combining autograft and homograft with TORPs and PORPs.     

The influence of middle ear pressure on the vestibular nerve activity in cats

The influence of middle ear pressure on the vestibular nerve activities was investigated in anesthetized cats. The vestibular nerve activities were recorded intraaxonally and positive or negative pressure was applied to the middle ear cavity through a tympanic membrane perforation. The firing of vestibular nerve fibers, especially the regular type nerve that responded to horizontal semicircular canal stimulation, increased with positive pressure and decreased with negative pressure. Most vestibular nerves that responded to anterior or posterior semicircular canal stimulation were not influenced by changes in the middle ear pressure. These results indicate that middle ear pressure load is transmitted to the vestibular end organs and then to vestibular nerve.     

Surgical treatment for the aberrant internal carotid artery in the middle ear with pulsatile tinnitus

Many previous reports have indicated that pulsatile tinnitus caused by an aberrant internal carotid artery (ICA) should not be treated surgically because of the risk of infection or aneurysm formation. We herein describe a case of aberrant ICA treated by middle ear surgery for which we introduced a novel approach. An 84-year-old man was presented with a one-year history of tinnitus in his right ear. Otoscopic examination demonstrated a whitish mass in the antero-inferior quadrant of the tympanic membrane associated with rhythmic pulsation. Images obtained by CT, MRI and MRA revealed protrusion of the ICA into the tympanic cavity, making contact with the tympanic membrane. Surgery to separate the tympanic membrane from the ICA was performed in order to relieve the pulsatile tinnitus. After the operation, the patient's aural activity was preserved and the tinnitus did not recur within a follow-up period of one year. In the present case, delicate middle ear surgery was effective for relief of the tinnitus. When treating patients with aberrant IAC showing features similar to the present case, the surgical approach we have described is worth attempting.     

Temporal bone histopathologic findings in drowning victims

The human temporal bones of five drowning victims, the largest such series, to our knowledge, were evaluated to determine what histopathologic changes occurred. Thickening of the periosteal epithelium, especially on the surgical dome of the otic capsule, was evident in all cases. There was also hemorrhage in the middle ear cavity in four of the cases. In the fifth case, a cholesteatoma and ruptured tympanic membrane were observed, but there was no evidence of hemorrhage. It is proposed that an intact tympanic membrane is needed to create sufficient negative pressure in the middle ear cavity to cause rupture of the blood vessels and hemorrhage. Such bleeding is indicative of drowning when the tympanic membrane is intact.     

Middle ear schwannoma--case report

Schwannoma is one of the common benign middle ear space tumors. The tumors may present with facial nerve paresis or palsy, otologic symptoms and/or parotid mass middle ear schwannomas may originate from the nerves of the tympanic caviti or by extensions from outside the middle ear space. Schwannomas of the facial nerve can occur along any segment, but they frequently involve the geniculate ganglion and extend proximally or distally from there. MRI and CT imaging characteristics are similar to those of vestibular schwannomas. We present the clinical and radiologic features of a middle-space schwannoma originating from facial nerve. The patient underwent middle ear exploration and mastoidectomy. The tumor was of facial nerve origin and was separated from middle ear. The pathologic diagnosis was schwannoma.     

Histopathological studies of intratemporal growth behavior of middle ear carcinoma

BACKGROUND: Otological hemorrhage otorrhea, and pain are amongst the first clinical signs of the middle ear carcinoma, which is usually diagnosed in advanced stages. Sudden deafness, facial nerve paralysis, and other symptoms of inner ear damage may be observed in the final stage. However, middle ear carcinoma is diagnosed extremely seldom in its early stages. The clinical management of this pathology is based on the knowledge of the tumor's pathways and its anatomic behavior. METHODS: Our study investigated 20 cases of middle ear carcinomas from the Wittmaack temporal bone bank (14 squamous cell carcinomas, 5 adenocarcinomas, and 1 adenoidcystic carcinoma) to analyze the behavior of the tumor growth and its influence on clinical symptoms. The aim was to determine criteria for early clinical diagnosis. RESULTS: The tumor arises in different regions of the temporal bone, and varying symptoms will subsequently reflect its pathway. When the tumor is confined to the middle ear area, its main location is the hypotympanum from which tumor spreads into the eustachian tube and, via infiltration of the adjacent bone structures (anterior wall of the middle ear), into the tensor tympani muscle and the sympathetic plexus of the internal carotid artery. Destruction of the ossicles was observed in the mid-tympanic cavity, and often only a thin layer of fibrous tissue from the Fallopian canal separated the tumor from the facial nerve (this nerve was rarely affected directly). The medial wall (labyrinthine wall) of the tympanic cavity remained intact in the majority of examined cases. The tympanic sinus, the round window niche, and the oval window niche did not show tumor infiltration. In the epitympanum, the tumor grew and infiltrated the adjacent mastoid. Larger tumors affected the internal auditory canal and infiltrated the acoustic nerve and the labyrinth. CONCLUSION: Improving the poor prognosis of middle ear carcinoma requires early diagnosis based on axial computed tomography (CT). Important factors in patient selection include age (50-70 years), sex (mostly women), and especially clinical symptoms (otorrhea, pain, hearing loss).     

Middle ear osteoma: a rare cause of conductive hearing loss with normal tympanic membrane

Osteomas of the temporal bone are benign osseous tumors usually located to the external auditory canal. Osteomas involving the middle ear are very rare. We report the case of a patient presenting with a progressive hearing loss caused by a middle ear osteoma involving the incus and contiguous to the tympanic segment of the facial nerve. This report highlights the value of CT scan in the work-up of conductive or mixed hearing loss with normal tympanic membrane. The management of middle ear osteoma is discussed.     

A minimally invasive technique for endoscopic middle ear surgery

Middle ear endoscopy should be considered a useful adjunctive or alternative method to microscopic surgical exploration for middle ear pathology. This minimally invasive technique provides excellent visualization for viewing the surgical micromorphology and pathological findings of the middle ear. Selected patients underwent middle ear endoscopy using a transtympanic approach. Rigid endoscopes of 2.7 mm and 1.9 mm caliber and 0°, 30° and 70° viewing angles were introduced into the tympanic cavity through small tympanostomy incisions. The indications and technique with video monitoring are discussed.     

Reconstruction of the tensor tympani tendon

We describe a case in which reconstruction of the tendon of the tensor tympani muscle was necessary for the successful restoration of sound conduction. The right ear of a nine-year-old boy was treated for cholesteatoma with staged surgery. During the first operation, the tendon was cut to ensure good visibility in the tympanic cavity. Post-operatively, maintenance of aeration of the middle ear required ventilation tubes at first and Valsalva manoeuvres later on. The position of the reconstructed tympanic membrane varied a great deal, moving between the medial wall of the tympanic cavity and extreme bulging. This made exact measurement of a columella for ossicular reconstruction impossible. The preserved handle of the malleus was bound to the cochleariform process with ionomer cement, using a piece of surgical suture material as a substitute for the tendon. This arrangement prevented the tympanic membrane from undergoing excessive lateral movement after inflation and the ossicular chain was replaced with a successful ossiculoplasty with an autogenous bone 'drum to footplate' columella. The pre-operative 55.0 dB air-bone gap decreased immediately to 3.3 dB, widening after three years to 15.0 dB.     

Partial oxygen tension of middle ear cavity in a normobaric environment

The present theory of eustachian tube function and middle ear ventilation posits that oxygen absorbed by the middle ear mucosa causes negative middle ear pressure which is relieved by periodic opening of the eustachian tube during swallowing and yawning. Measured by a PO2 sensor (Clark type) inserted into the middle ear cavity of normal adults through the eustachian tube, the partial oxygen pressure of the tympanic cavity was found 53.7 +/- 6.5 Torr (N:22). It was about one-third of ambient pressure (about 150 Torr), and showed no change when the eustachian tube was opened by swallowing. Our second study measured the effect of alterations in the systemic arterial blood oxygenation on middle ear gas exchange in 23 guinea pigs ventilated using 21% (room air), 50%, 70% and 100% oxygen at constant carbon dioxide blood gas tension. Partial oxygen tension (PO2) of middle ear cavity was measured by inserting a PO2 sensor into the tympanic bulla through a bore hole. The following results were obtained: (1) PO2 of the middle ear cavity was 39.3 +/- 2.2 Torr at room air, 42.2 +/- 0.84 Torr at 50%, 46.6 +/- 1.1 Torr at 70% and 54.5 +/- 3.7 Torr at 100% oxygen breathing. (2) There was a significant correlation between PO2 of the middle ear cavity and systemic arterial hyperoxygenation noted. Y = 30.79 + 0.056.X (r = 0.9440) (3) The rate of oxygen diffusion in the middle ear cavity was 2.665 x 10(-5) ml/min/cm2 and the rate of oxygen absorption in the middle ear space was 2.874 x 10(-5) ml/min/cm2. No significant difference between the rate of diffusion and that of absorption of oxygen in the middle ear cavity was noted. In our third study, electron microscopy shows that the submucosal capillaries of the human mastoid cells are structures which facilitate the intra- and extravascular transport of substances. It is known from these results that tympanic cavity pressure is kept equal to ambient pressure, or slightly higher to atmospheric pressure, by the respiratory function of the middle ear and mastoid cells so that outflow of air from the tympanic cavity to the pharyngeal orifice occurs during the ventilation of the eustachian tube at ambient pressure and inflow of air from the pharynx to the tympanic cavity is prevented in the absence of environmental pressure changes. The middle ear cavity has respiratory function, and in particular, such function of the mastoid cavity, which is larger in volume than the tympanic cavity, plays a significant role.(ABSTRACT TRUNCATED AT 400 WORDS)     

Metastatic seminoma of the temporal bone

Temporal bone metastasis of classic testicular seminoma is extremely rare in the English literature. Except for a clinical case report of seminoma in the temporal bone, to our knowledge there is no temporal bone pathology report of secondary seminoma. In the left temporal bone of the present case, tumor cell infiltration was found in the external auditory canal, tympanic membrane, middle ear cavity, tympanic and mastoid mucosa, tensor tympani muscle, and so on.     

Polytomography and congenital external and middle ear anomalies

The preciseness of the detail which can be demonstrated by multidirectional tomography makes it a useful and almost essential method of examination of congenital anomalies of the external and middle ear. Multiple examples are described which are of inestimable value to the surgeon in the diagnosis and surgical correction of anomalies of the temporal bone. Variations of the external canal, temporomandibular joint, pneumatization of the temporal bone, tegmen, tympanic cavity, ossicles, oval and round windows, jugular bulb and carotid artery and facial nerve as seen by polytomography are described.