Cerebellopontine Angle Lipoma in an Asymptomatic Patient: A Case Report
Introduction: Lipomas account for approximately 0.15% of the cerebellopontine angle tumors. Audiometry usually shows unilateral or asymmetric sensorineural hearing loss with low speech recognition index. MRI is the gold standard for diagnosis, with no image enhancing with gadolinium, and positive fat suppression. Treatment is usually conservative and surgery is reserved for clinically untreatable dizziness, trigeminal neurology, and headache.
Case report: GPS, male, 30 years old, referred to our center after periodic audiometry. Pure tone audiometry revealed a mild flat curve sensorineural hearing loss at the left ear and the auditory brainstem response (ABR) a prolonged I-III interval at the same ear. The MRI> showed a small elongated extra-axial image, fat-like signal, and 0.8-cm diameter at the superior portion of the left cerebellopontine angle cistern. The lesion was not seen with the fat suppression technique. Neurosurgery opted for conservative management. One year later, audiometry and MRI were performed again, with no changes
Discussion: Unlike most of the reported cases, the patient was asymptomatic at the diagnosis. The audiometric findings are compatible with retrocochlear lesions, as well as the ABR findings. As for all the retrocochlear tumors, MRI is the gold standard for diagnosis, and, particularly for lipomas, the absence of enhancing with gadolinium and the disappearing with the fat suppression technique determine the clinical diagnosis. There seems to be a consensus in favor of conservative management concerning the slow growth. Surgery is reserved for the clinically untreatable and disabling symptoms.