Steroid responsive fluctuating sensorineural hearing loss due to juvenile pilocytic astrocytoma involving the cerebellopontine angle.

Tumors of the cerebellopontine angle (CPA) are common and represent up to 10% of all intracranial tumors. Rarely, intrinsic brainstem tumors can involve the CPA and present with auditory symptoms typical of CPA tumors such as hearing loss, vertigo and tinnitus. We report on a rare case of an intrinsic brainstem neoplasm presenting with steroid responsive fluctuating sensorineural hearing loss in a child. The patient initially presented with an acute worsening of an unilateral sensorineural hearing loss, without additional symptoms, that responded to oral steroids. Otoacoustic emission testing demonstrated normal outer hair cell function suggesting retrocochlear pathology. Magnetic resonance imaging with contrast enhancement revealed an intrinsic neoplasm of the middle cerebellar peduncle impinging on the 7th/8th neurovascular bundle within the CPA. The patient underwent gross total resection of the juvenile pilocytic astrocytoma via retrosigmoid craniotomy and remains disease free at 2 years postoperatively. This case highlights that suspicion of central nervous system pathology should be heightened in the presence of steroid responsive, fluctuating sensorineural hearing loss with normal outer hair cell function.