Norihiko Ishikawa

Histopathological Examination of Ruptured Carotid Artery after Irradiation

We report 2 cases of carotid artery rupture after irradiation that was performed 1 year and 17 years before the ruptures. When irradiation-induced arterial rupture occurs, it usually does so within a few months following irradiation. However, the histopathological sections obtained in the present cases revealed carotid artery necrosis that was presumably induced by irradiation. Carotid artery rupture is sudden, massive hemorrhage that ranks among the most dreaded complications in the head and neck. However, several patients have been saved by hospital personnel who discovered the rupture in time to take appropriate measures such as cleaning of the wound and protection with myocutaneous or myofascial flaps. Therefore, it is important to be aware of the possibility of rupture or perforation of major vessels after irradiation, even when the radiation therapy was performed a long time ago.

Lipoma in the deep lobe of the parotid gland: a case report

We report here on a rare case of lipoma in the deep lobe of the parotid gland. MRI revealed that the tumour was situated mainly in the deep lobe and it extended posteriorly and medially into the space between the sternocleidomastoid muscle and the posterior belly of the digastric muscle, with slight extension into the parapharyngeal space. This tumour produced strong signals on T1- and T2-weighted MR images and weak signals on fat suppression images. In addition, MRI clearly showed the margin of the tumour, which enabled us to readily distinguish the tumour from the surrounding adipose tissue. The images suggested a diagnosis of deep lobe parotid lipoma with posteromedial extension to the sternocleidomastoid muscle, which proved true at surgery. We thus believe that MRI is highly useful, perhaps even necessary, in diagnosing tumours of the head and neck.

A case of myoepithelioma arising in an accessory parotid gland.

The present paper describes the first reported case, to our knowledge, of a myoepithelioma arising in an accessory parotid gland. Because pre-operative fine-needle aspiration cytological findings and operative findings suggested that this tumour was malignant, the decision was made to remove the tumour surgically along with the buccal branches of the facial nerve. The resected nerve was reconstructed by nerve transplantation, using the great auricular nerve. Subsequently the tumour was found to be benign. One year after surgery, the patient had excellent facial nerve function and so far there has been no evidence of recurrence.

Sonotubometric Measurement of the Eustachian Tube Function by Means of Band Noise

The Eustachian tube is well known as an organ serving the ventilation and drainage of the tympanic cavity and mastoid. Ventilation is carried out by the opening and closing of the Eustachian tube accompanying swallowing movements. Until now there has been no instrument to quantify these motor activities of the tube necessary for its function as a ventilator. The author developed a generally applicable sonotubometer Model WIO-01 with the help of Siemens Hearing Institute K.K. for automatic measurement of the aforesaid tubal function with the use of 7 kHz full-octave band noise. In a sonotubometric trial with 32 adult female subjects, the duration of patency of the Eustachian tube was 288.5 +/- 1.38.5 ms, and the amplitude eliciting response was 16.4 +/- 8.3 dB. The positive response rate was 89.1%. In 89 children aged 4-12 years, a positive response was detected in 117 ears (61.9%). The mean duration of patency was 337.7 +/- 154.4 ms, and the amplitude 16.3 +/- 7.2 dB. It is physiological to have tubal opening and closing during natural swallowing. It is therefore important to understand the tubal function when dealing with tympanoplasty and diseases caused by tubal dysfunction.

Meningioma of the internal auditory canal with extension into the vestibule

Meningiomas account for approximately 18 to 19 per cent of all brain tumours. Although they can arise in numerous locations, meningiomas of the internal auditory canal (IAC) are rare. Most tumours that originate in the IAC are schwannomas of the VIIIth cranial nerve (acoustic neuromas). We report a case of a meningioma which appears to originate from the IAC and extends into the vestibule. The clinical findings and the radiographical features of meningiomas of the IAC are similar to those of acoustic neuromas. Pre-operative differentiation between acoustic neuromas and meningiomas of the IAC may be difficult.

Solitary infantile myofibromatosis in the lateral orbit floor showing spontaneous regression.

Infantile myofibromatosis is a rare benign tumour usually occurring early in infancy. We describe the case of a 10-year-old boy with solitary infantile myofibromatosis in the left lateral orbit floor which regressed spontaneously. Although our patient was older than previously reported cases and showed bony destruction confirmed by computed tomography (CT), this tumour was diagnosed as infantile myofibromatosis based on immunohistochemical findings. The tumour disappeared spontaneously six months after incisional biopsy, that also indicated this tumour was an infantile myofibromatosis.

Surgical Approach to Tumors Arising from the Posterior Two Thirds of the Nasal Septum

A surgical approach to tumors of the septum is discussed. Two patients who had tumors in the posterior two thirds of the septum are shown in this paper. One had a benign mixed tumor and the other had an extramedullary plasmacytoma in the posterior two thirds of the septum. They underwent resection of the tumors with the septum by lateral rhinotomy. The first case additionally underwent an oval-shape resection of the palate. The postoperative profiles of the nose are good.

An Extracranial Trigeminal Neurinoma Expanding into the Infratemporal Fossa; A Case Report.

A 21-year-old male with an extracranial trigeminal neurinoma is presented. Swelling of the pre-auricular region was noted in 1998 and the patient consulted in one of our clinics. CT scan and MRI demonstrated a lesion consisting of five linked nodules that seemed to extend along the extracranial course of the mandibular nerve, passing between the medial and lateral pterygoid muscles and extending laterally toward the medial aspect of the compressed parotid gland. The anterior condyle of the mandible was displaced. Pathological diagnosis by fine needle aspiration biopsy showed neurinoma. The tumor seemed to originate from the mandibular nerve. After the diagnosis was established, the patient was observed for 2 years without surgery. In 2000, repeat CT examination demonstrated that the tumors had enlarged and erosion of the oval foramen had progressed. Therefore, surgical treatment was indicated. Surgery was performed in September 2000. A bicoronal skin incision was made with extension to the periauricular and cervical area. An infratemporal extradural approach combined with a zygomatic and mandibular osteotomy. The moniliform tumor was totally extirpated. Postoperatively, the patient displayed sensory defects of the mandibular nerve and trismus. The latter was improved by rehabilitation one year postoperatively.

Ethyl Loflazepate in the Treatment of Tinnitus

Ethyl loflazepate (Meilax®) was administered orally to 91 patients suffering from tinnitus, 58 with tinnitus and sensorineural hearing loss, 27 with tinnitus without hearing loss, and 6 with tinnitus accompanied by sudden deafness. The clinical severity of tinnitus was evaluated every two weeks in terms of loudness, continuity and annoyance. Medication was rate of as effective in 27.5%, moderately effevtive in 33%, slightly effective in 17.6% and not effective in 21.8% at the end of treatment. Effectiveness depend on the duration of treatment. Patients treated for a relatively long period showed greater clinical improvement. Two patients complained of sleepiness as a side effect. It was concluded that ethyl loflazepate is effective in reducing severity of tinnitus.

Aeration of the tympanomastoid cavity and eustachian tube function.

The degree of opening and closing of the eustachian tube varied with changes in body position. However, neither the duration of auditory tube opening and closing nor the opening pressure varied.The physiological reason for such findings appears to involve the anatomic course of the pharyngeal orifice of the auditory tube and of the auditory tube itself, protecting the middle ear cavity from invasion by secretions and from infections. When a patient with mild dysfunction of the auditory tube lies on his side, the middle ear cavity pressure becomes markedly positive. Involvement of congestion in the venous plexus of the middle ear cavity and of gas emission is suggested in this shifting of tympanic compliance to the positive pressure side with change in head position or when lying on the side. These findings, show that the ventilation of the middle ear cavity under environmental pressure, keeping the internal pressure of the middle ear cavity equal or slightly higher than atmospheric pressure at all times, serves to maintain the conductive efficiency of the middle ear cavity through adjusting of the internal pressure of the middle ear cavity to atmospheric pressure by the opening and closing of the auditory tube.