Acoustic neuroma is a rare noncancerous tumor. It grows slowly from an overproduction of Schwann cells and is also called a vestibular schwannoma. The tumor then presses on the hearing and balance nerves in the inner ear. Schwann cells normally wrap around and support nerve fibers. A large tumor can press on the facial nerve or brain structures.
There are 2 types of acoustic neuromas:
Unilateral acoustic neuromas. This type affects only one ear. It is the most common type of acoustic neuroma. This tumor may develop at any age. It most often happens between the ages of 30 and 60. Acoustic neuroma may be the result of nerve damage caused by environmental factors. No environmental factor has been shown to cause acoustic neuromas.
Bilateral acoustic neuromas. This type affects both ears and is inherited. It is caused by a genetic problem called neurofibromatosis-2 (NF2). The treatment for acoustic neuromas depends on the size of the tumor and the patient’s age, general health and preferences, and may involve surgery, radiosurgery and sometimes observation.
Surgeons have developed several types of craniotomy to remove acoustic neuromas. Surgical craniotomy may use a suboccipital, translabyrinthine approach or middle fossa approach.
• Radiosurgery
Radiosurgery treatments can be single or fractionated (multiple smaller treatments rather than one large one). Fractionated stereotactic radiosurgery (FSR) (Gamma knife) appears to offer very high rates of control with preservation of hearing and preservation of the facial strength.
• Observation
For some slow-growing acoustic neuromas observation with delayed treatment may be acceptable. This is a common treatment option for elderly or infirm patients with mild symptoms where the risks of therapy may be greater and where the tumor may not grow during their lifespan.