Medium and large acoustic neurinomas with normal tonal audiometry at the moment of diagnosis

INTRODUCTION: Early diagnosis of an acoustic neurinoma for any possible treatment is important, especially in view of the relationship between surgical morbidity and the size of the tumour. The commonest presenting symptom of these tumors is unilateral perceptive deafness. However, between 4 and 12% are diagnosed before deafness occurs, although they may be large in size. Therefore one should remember other symptoms which lead to suspicion of these tumors, and have diagnostic guidelines available to allow the earliest possible detection. PATIENTS AND METHODS: We report four cases of acoustic neurinoma or vestibular schwannoma of medium or large size in which audiological studies did not at first give rise to suspicion of the presence of this tumour, since audition was considered to be normal at conversation frequencies (500 to 3,000 Hertz) for the age of the patient or who had an audiometry curve with symmetrical deafness in both ears. CONCLUSION: We evaluated the diagnostic importance of the tests done and compared the results with data published in the literature.