It is a typical nerve sheath tumor that originates from the vestibular nerve sheath. Since there is no involvement of the auditory nerve itself, the name auditory neuroma is inappropriate and should be called: vestibular nerve sheath tumor. This tumor is one of the common intracranial tumors. This tumor occurs in middle-aged people, with a peak at the age of 30 to 50 years, the youngest at 8 years, and the highest age can be over 70 years. Most of the tumors occur in the vestibular segment of the auditory nerve, and a few occur in the cochlear part of this nerve. As the tumor grows larger, it compresses the lateral surface of the pontocerebellum and the anterior border of the cerebellum, filling the pontocerebellar horn recess of the cerebellum. Most of the tumors are unilateral, but a few are bilateral; if accompanied by neurofibromatosis, the sides are reversed. It is a benign lesion and can often be cured permanently if it can be completely removed. However, because the tumor is adjacent to the brainstem and other important structures, it is a great challenge for neurosurgeons to remove it surgically. 1.What are the non-surgical treatments? (1) Expectant therapy: For old, frail and small tumor patients, close clinical observation is the best choice, except for tumor growth is found to be fast. For younger patients, expectant therapy is controversial. (2) Stereotactic radiosurgery: i.e., r-knife, usually this procedure is indicated for patients with a single lesion and less than 3 cm. The principle is to irradiate the tumor tissue with a focused beam of radiation, thus terminating the growth of the auditory neuroma and trying to protect the surrounding normal tissues. r-knife has the same postoperative complications as other microdissection procedures. Its most common complications are temporary facial palsy, hearing impairment (mostly permanent), and hydrocephalus. Studies have found that when surgery is performed again after r-knife treatment, it is more difficult and complications increase. 2.What are the surgical treatments? Most surgeries for auditory neuroma can be performed with one of the following three surgical approaches: middle cerebral fossa approach; suboccipital approach; and vagal approach. However, if the patient still has effective hearing before surgery, hearing preservation is often used, and the choice of surgical approach has evolved from a single unilateral posterior suboccipital sigmoid sinus approach to a posterior sigmoid sinus approach via the internal auditory canal. If the patient has preoperative hearing loss, then the labyrinthine approach will be the most direct procedure to remove the tumor, regardless of tumor size. The benefit of intraoperative facial nerve monitoring to maximize preservation of facial nerve function is clear. It is also the standard approach to surgery currently recommended by the NIH survey centers. As for methods of preserving hearing, several testing techniques have been reported, with ABR and cochlear electrograms being the most basic methods. When the waveforms are monitored for integrity at the end of the procedure, especially the I and V waves, hearing preservation is highly likely. Of course, there are a few unexpected cases. The cranial middle fossa approach is a technically difficult procedure due to the lack of obvious intraoperative landmarks and the restricted operative field. This procedure is indicated for smaller auditory neuromas, where the tumor must enter the pontocerebellar horn of the cerebellum less than 5 mm. Since this procedure is hearing preserving, it requires that the patient has good hearing preoperatively. The current recommended criteria are: threshold of speech reception greater than 30 dB and speech discrimination greater than 70%. However, when the patient has poor preoperative hearing, a vagal approach should be chosen. This procedure preserves hearing in 52% of patients, 68% of patients will still retain useful hearing, and 95% of patients have facial nerve function in House-Brackman class I and II.