The area behind the ear, where our brain stem and cerebellum are adjacent, is called the corner. In this region, it is often found in acoustic neuroma,  meningioma, epidermoid tumor and similar tumors. Acoustic neuroma, which constitutes the majority of tumors of this region, will be mentioned here. Acoustic tumors are benign, encapsulated tumors arising from Schwan cells, which originate from the eighth nerve, which goes from the brain stem to the ear structures and is responsible for the hearing and balance system. This region is also found in the five, seven, nine, ten, eleven, and twelfth nerves.

 

It constitutes 6-8% of all intracranial tumors. Women are affected slightly more often. It can be familial (with Neurofibromtosis) (5%) or sporadic (single) (95%). It often originates from the inferior vestibular nerve, less frequently from the superior vestibular nerve. It constitutes 78% of corner tumors. 50% of acoustic neuromas grow 1-2 mm per year and the growth rate is generally constant.

 

Symptoms:

It does not give any symptoms up to a certain size, because the structure it emerges from is not the nerve element, but the sheath that protects the nerve. The first symptom in the diagnosis of the disease is usually hearing loss. Initially, the patient does not hear high-pitched sounds on the phone and misses the conversation. As the mass grows, hearing is gradually lost and eventually deafens the patient. There is not always a proportional situation between the size of the tumor and the damage it does. Later, signs of imbalance, tinnitus (ringing) and increased intracranial pressure (headache, vomiting) may occur. The facial nerve (seventh nerve), which operates the facial muscles, is stretched by sticking on the tumor, and the facial nerve tolerates this tension very well and facial paralysis is not seen until very late stages. After the tumor begins to grow, symptoms related to other nerves and increased intracranial pressure begin to appear.

 

Diagnosis:
The diagnosis of the tumor is made by MRI and CT. Hearing tests should also be done in patients.

 

Treatment:

The first option in the treatment of the tumor is surgery. The patient's age, hearing status, tumor size and surgeon's experience are important in the selection of the surgical method. Facial paralysis and further hearing loss may occur frequently. For this reason, recently, radiosurgery (gamma knife and cyber knife, etc.) can be used in leions smaller than 2 cm and the results have been shown to be good. Radiosurgery can also be combined with surgery. To avoid complications, the tumor can be reduced and radiosurgery can be performed.

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