Objective: This study aimed to quantify the atypical presentations of patients with vestibular schwannoma by applying the audiologic criteria for the treatment of patients to the Cambridge series of such tumors to show that clinical acumen is necessary for the effective screening of these tumors.
Study design: This study was a retrospective case review of 473 patients with vestibular schwannoma.
Setting: The surgery was conducted at the Department of Otoneurological and Skull Base Surgery, University Hospital, Cambridge, a tertiary referral center.
Patients: A total of 473 patients with a unilateral sporadic vestibular schwannoma were studied.
Main outcome measures: Measured were the principal presenting symptoms and the criteria for audiologic management.
Results: Of this series of patients, 89.3% had a principal presenting symptom that was typical of vestibular schwannoma (hearing loss: progressive or sudden, imbalance or tinnitus) and 10.7% had an atypical principal presenting symptom. This group of patients had significantly larger tumors (Mann-Whitney U test; tied p value = 0.0002), shorter length of history (tied p value < 0.0001), and better preserved hearing (tied p value < 0.001) than the typical otologic presentation group. These clinical correlates are related to tumor morphology, and it is hypothesized that the site of the neurilemmal-glial junction (medial or lateral) has an effect here. If the U.S. criteria for the treatment of a patient by an audiologist are applied to this series of patients, then 7 patients (1.5%) would not have had the diagnosis of vestibular schwannoma. If the U.K. criteria are applied, this number of missed tumors is 17 (3.6%). The addition of unilateral tinnitus as an indicator of the need for otologic investigation reduced the number of patients who might be missed to 2 (0.42%) for the U.S. cases and 5 (1.1%) for the U.K. cases.
Conclusions: Of patients with vestibular schwannoma, 10.7% have an atypical principal presenting symptom, and this group of patients has significantly larger tumors than those patients who present typically. This finding is of particular relevance to the entry point of such cases to the healthcare system. A number of patients with vestibular schwannoma appear to pass the criteria for treatment by an audiologist without reference to an otologic opinion. These patients may not be investigated from an early stage with potential implications for increased morbidity.