Intracranial lipomas affecting the cerebellopontine angle and internal auditory canal: a case series

To assess the long-term outcome of lipomas affecting the cerebellopontine angle (CPA) and internal auditory canal (IAC). This is a retrospective, single-center study of 10 CPA and IAC lipomas that have presented for the last 6 years. There were 8 male and 2 female patients whose age ranged from 22 to 71 years. These lesions were distributed equally between left and right sides. The natural progression, audiovestibular signs and symptoms, imaging characteristics, and management options have been evaluated. Long-term clinical outcome was correlated with serial imaging and audiograms. The most common presenting feature was hearing loss with an average lesion size of 8 mm. Two patients experienced imbalance, with one requiring operative intervention for incapacitating vertigo. The other 9 were managed conservatively. Follow-up imaging was available for 8 cases, and no growth was observed in any of these, with an average follow-up of 3.5 years. Because of the resolution of modern imaging, lipomas of the IAC and CPA are increasingly being recognized and accurately diagnosed. Our data suggest that these lesions are more common than previously thought, representing approximately 1% of all lesions in this location referred to our center. With the absence of growth in 8 cases with follow-up average of 3.5 years as our basis, we recommend that these lesions are managed conservatively by serial imaging. In rare cases, surgery may be required if the lesion is resulting in incapacitating symptoms, such as significant balance disturbance.