The main manifestations of acoustic tumors are progressive or acute sensory hearing loss, tinnitus, and dizziness. The subjects of this study, which was performed with the aim of clinical characterization of acoustic tumors, were 26 patients who visited Dokkyo Medical University Hospital and were diagnosed as having acoustic tumors. We examined the symptoms, the relationship of the type of hearing loss or the presence/absence of dizziness, the tumor diameter and rate of tumor progression.

　Hearing loss was the most frequent early symptom and was seen in 20 of the 26 patients. Ten patients complained of dizziness, and all of these patients also had hearing loss. While the type of hearing loss varied, high-tone sensorineural hearing loss was the most common type. Sensorineural hearing loss with a flat configuration of the audiogram (horizontal sensorineural hearing loss) was recognized in the patient groups with small-, middle-, and large-sized tumors, but not in the group with inner ear canal tumors.

　In regard to the relationship of the symptoms with the rate of tumor progression, horizontal sensorineural hearing loss was observed in the group with progressive posterior cranial fossa tumors, but not in the group with non-progressive posterior cranial fossa tumors.

　There was no relation between the presence/absence of dizziness and the tumor diameter or rate of tumor progression.

　In routine clinical practice, the possibility of acoustic tumors must be borne in mind, in addition to that of sudden hearing loss and Meniere's disease, in patients presenting with hearing loss and dizziness.

　We report a case of frontal sinus cyst extending to the right orbit. It was extremely difficult to remove the cyst via only the transnasal approach, because of a calcified lesion in the frontal fossa.

　The patient, 29-year-old woman, presented to our ophthalmology department with right eyelid swelling. Right eye protrusion was observed, however, there was no evidence of eyesight deterioration or eye movement disorder. She was referred to our department for further examination and treatment, because CT revealed a cyst-like lesion in the right orbit and frontal sinus.

　A calcified lesion was seen in the right frontal fossa, and a 3-cm cyst-like lesion was found in the superior intraorbital wall, and the lesion was found to extend into the frontal sinus.

　With the neurosurgeons' assistance, the frontal skin was lifted by a coronary incision. Thereafter, the lumen of the frontal sinus was confirmed by fenestrating the frontal bone.

　As a result, the lesion was found to be a frontal sinus cyst. We thought that it was a good indication for extranasal surgery, because the lesion was present outside the nasal cavity and the calcification was found in the frontal fossa. In this report, we mainly consider the operation methods for periorbital lesions.

　Nasal fibrous dysplasia is a rare type of benign fibro-osseous bone disease. Fibro-osseous bone disease is classified into 3 types, including fibrous dysplasia. Among them, ossifying fibroma can grow rapidly, especially in young patients, and can cause facial asymmetry, eye movement disorder and visual impairment. Therefore, diagnosis of the disease type is important. However, it is often difficult to make the diagnosis based on the clinical symptoms and imaging findings alone, and surgery is frequently performed for diagnosis and treatment of fibro-osseous lesions. I report a case of ethmoidal fibrous dysplasia that was treated by complete excision and skull base reconstruction by the transnasal endoscopic approach. In adult cases with no symptoms, observation alone might be appropriate. On the other hand, in patients with symptoms caused by the lesion or in young patients in whom the lesion close to the optic nerve or the skull base, operation surgery is indicated. If the symptoms are caused by the lesion, it is appropriate to excise it completely to prevent postoperative bone regrowth, especially in young patients. Otherwise, the lesion may be removed to the extent that no complications are caused by the operation. It is necessary to determine how to perform the surgery, not only based on the patient's background characteristics, but also by the skill level of the treating surgeon.