Contralateral tinnitus and hearing loss due to a tumor at the region of inferior colliculus: illustrative case

BACKGROUND: Subjective hearing loss resulting from unilateral lesions of the quadrigeminal cistern region or inferior colliculus is a rare entity. OBSERVATIONS: The authors presented the case of a 32-year-old man with a history of 4 months of nonpulsatile tinnitus and 1 month of unilateral sensorineural hearing loss. He was otherwise healthy with no significant previous medical history. Intravenous gadolinium contrast magnetic resonance imaging of the head revealed a lesion at the region of the left inferior colliculus suggestive of a lipoma. The tumor was removed, and the patient had no significant hearing change afterward, with an improvement in tinnitus. The histological examination demonstrated the tumor as a fibrolipoma. LESSONS: Contralateral subjective hearing loss is an uncommon presentation for a lesion in the region of the inferior colliculus.