Conservative management of unilateral acoustic neuromas

Objective: The aim of this study was to analyze the natural course of unila teral acoustic neuromas and to evaluate the advantages and disadvantages of an initial conservative approach. Methods: Between 1989 and 1994, 74 consecutive patients: with the diagnosis of unilateral acoustic neuroma were evaluated at the Department of Otorhin olaryngology, University of Zurich. Their charts and magnetic resonance ima ging scans were retrospectively analyzed regarding duration and type of sym ptoms, initial tumor size, tumor growth pattern, and audiometric data. Results: Of the 74 tumors, 68.9% (51/74) did not grow during a mean follow- up of 35 months. Eight (16%) of these tumors had radiologically documented tumor regression. Twenty-three tumors did grove, 16 of them (70%) with a gr owth rate of <2 mm/year. There was a statistically significant correlation be-tween the first-year and the total growth rate, indicating that the tumo r's behavior in the first gear is highly predictive of its subsequent growt h pattern. Patients with progressive hearing loss as a first symptom had a significantly lower tumor growth than those presenting with tinnitus, sudde n hearing loss, or dizziness. Patients with tumor growth showed a greater t endency for hearing loss, although this trend was significant only for isol ated frequencies. In 12% of the cases (9/74), the initial conservative appr oach had to be abandoned in favor of surgery. Conclusion: Watchful expectation can be regarded as a safe approach for sel ected cases of acoustic neuromas. Surgery or irradiation is indicated in pa tients with proven growth of their tumors.