Acoustic neuromas : Differential diagnoses

Abstract

Acoustic neuromas in adults are the most common infratentorial tumors that originate from the Schwann's cells of the vestibular part of the eighth cranial nerve and are clinically noticeable through neurological deficits, such as unilateral hypoacusis, tinnitus, dizziness and unilateral facial nerve palsy. Due to the widespread use of computed tomography (CT) and magnetic resonance imaging (MRI), acoustic neuromas can now be diagnosed with ahigh rate of sensitivity and specificity; however, there are anumber of possible differential diagnoses, such as meningioma, epidermoid and metastases as well as anumber of less common diagnoses, such as peripheral nerve sheath tumors, sarcoidosis/neuritis and lipomas, which are sometimes difficult to distinguish from acoustic neuromas. Particularly smaller findings can often only be differentiated with the aid of ahistopathological investigation. Small intrameatal and asymptomatic acoustic neuromas, some of which are discovered as incidental findings, do not require immediate treatment and should instead be monitored by MRI. Larger findings that are symptomatic and thus cause anumber of severe neurological symptoms that are stressful for the patient, should be surgically removed. In cases where surgical treatment is not possible or for smaller symptomatic findings, radiotherapy can also be considered as an alternative.