Malignant Melanoma of the Temporal Bone Initially Presenting with Dizziness

A 48-year-old male presented to the otolaryngology outpatient clinic with a 3-month history of dizziness. Physical examination showed horizontal nystagmus toward the left on left lateral gaze and an intact tympanic membrane. No other neurological abnormalities were observed in the neurology department consultation. Thus, vestibular neuritis was suspected, and conservative treatment (dimenhydrinate, flunarizine, and ginkgo biloba leaf extract) was thus carried out. On follow-up after 1months, the dizziness symptom was maintained. Caloric tests were underwent and demonstrated right-sided unilateral weakness of 70%. On the ENT outpatient department after 2 months, the symptoms had relapsed and right pulsatile tinnitus and diplopia were noted. Puretone audiometry showed mild, mixed-type hearing loss in the right ear. Computed tomography (CT) of the temporal bone showed a soft tissue density from the right mastoid to the petrous apex with bony erosion. The lesion extended to the middle ear cavity at the cochlear promontory (Fig. 1). Magnetic resonance imaging (MRI) revealed an approximately 4.5 cm, irregularly contoured mass centered at the right petrous apex. The mass showed iso-to-low signal intensity on T2-weighted images and heterogeneous high-signal Malignant Melanoma of the Temporal Bone Initially Presenting with Dizziness