Cerebellopontine angle lipoma: Case report and review of the literature

Intracranial lipomas located in the cerebellopontine angle are extremely ra re. These rumours are maldevelopmental lesions which can cause slowly proge ssive neurological symptoms. The clinical management of these rumours diffe rs significantly from other lesions in this region. A 27 year old woman pre sented with a 2-month his tory of vertigo and a slowly progressive deterior ation of hearing in the left ear. Computed tomography (CT) revealed a large low-density mass in the left cerebellopontine angle without any contrast-e nhancement. Ln T1-weighted magnetic resonance imaging (MRI) the lesion was hyperintense and did not enhance after application of gadolinium. Areas of lower signal intensity inside of the lesion were suggested as incorporated cranial nerves. A left retrosigmoidal approach in a semi-sitting position w as chosen to expose the tumour. After reducing the tumour mass, the tumour was dissected from the cranial nerves which were incorporated into the tumo ur. The residual tumour was adherent to the brain stem and the encased lowe r cranial nerves, allowing only a near subtotal resection of the highly vas cularized tumour in order to avoid neurological deficits. The histological examination revealed a lipoma. Attempts at complete removal of cerebellopon tine angle lipomas usually result in severe neurological deficits. Conserva tive treatment should therefore be prefered. Limited surgery is indicated i f the patients suffer from disabling neurological symptoms and signs e.g., vertigo, nausea, trigeminal neuralgia, facial weakness or facial spasm.