Radiologic Features of Spontaneous Regression of Vestibular Schwannomas

Vestibular schwannoma (VS) is the most common benign tumor originating in the cerebellopontine angle. In most cases, tumors tend to grow and deserve proper treatment. Sometimes they stabilize, and rarely they decrease in size spontaneously. We evaluated retrospectively the images of patients with spontaneous tumor regression. We describe the common neuroimage findings of patients with spontaneous tumoral regression. Four patients with diagnosis of VS were followed with magnetic resonance imaging (MRI). There were some relevant features in MRI: a heterogeneous contrast enhancement in the outer layer of the tumor and presence of a cerebrospinal fluid column between the tumor and the entrance of the internal auditory canal. The percentage of tumor diameter reduction ranged from 20% to 40%. Some MRI features may demonstrate a spontaneous involution of VS and may be closely followed in asymptomatic or oligosymptomatic patients.