The Factors Associated with Tumor Stability Observed with Conservative Management of Intracanalicular Vestibular Schwannoma

Objective: Periodic observation with imaging is an acceptable option for patients with small vestibular schwannomas (VSs). The objective of this study was to evaluate the outcome of conservative management of intracanalicular VSs (ICVSs).

Methods: We reviewed 31 patients who were followed up for more than 1 year among patients diagnosed as having VS limited to the internal auditory canal. The median follow-up period was 31 months (range, 12-84 mo). We analyzed the patients' clinical features, clinical courses, and audiologic changes.

Results: The most frequent initial presenting symptom in patients with ICVS was hearing loss, and one-half of the patients (8 of 16) had a history of sudden hearing loss. Seven patients (22.5%) showed tumor growth during the follow-up period. When we considered the initial tumor size in ICVS, the patients larger in size than the median showed a significantly higher rate of tumor growth. In terms of the initial hearing levels of ICVS according to the Consensus Meeting Guidelines, five patients were classified as Class A (normal hearing) and six patients were classified as Class B. Only one patient among patients with useful hearing (Classes A and B) showed tumor growth. The follow-up hearing levels of all Class A patients were preserved; however, all Class B patients deteriorated to Class C.

Conclusion: Patients with ICVS showed favorable results with conservative management. Among them, patients with small tumors and normal hearing showed a good prognosis.