Unilateral tinnitus as a single symptom of unusually large vestibular schwannoma

Abstract

Introduction. Vestibular schwannomas are relatively rare tumors whose symptoms are based on its location and as the tumor grows, the symptoms usually advance. Case Report. An 18-year old patient was examined by an otolaryngologist due to buzzing in her right ear that had lasted for about 1 month. Her pure-tone audiometry findings showed slight asymmetry; a slight ascendant type sensorineural hearing loss was found in the right ear (25 dB HL at 125 Hz, 20 dB HL at 250 Hz, and 10 dB HL at other frequencies), while the threshold in the left ear was 15 dBHL at 125 Hz and 10 dB HL at other frequencies. Electronystagmography, otoacoustic emissions and auditory brain-stem responses suggested retrocochlear etiology of tinnitus. Magnetic resonance imaging examination revealed a large right cerebellopontine angle tumor, measuring 5 x 3 x 3 cm, which had shifted the brain stem laterally. Conclusion. Every case of unilateral tinnitus, asymmetric sensorineural hearing loss, or hypotonia of labyrinth not strictly accompanied by vertigo, needs to be further evaluated using a battery of audiologic tests whose findings may be normal. Audiologic tests should be repeated in cases of persistent symptoms and accompanied by cranial magnetic resonance imaging, which is today considered the gold standard for diagnosis of vestibular schwannoma.