A case of metastic melanoma of IACs with a rapidly decay of auditory and vestibular function

Melanoma is one of the tumours whose incidence has increased the most in recent decades.Metastasis of the inner ear and cerebellopontine angle from melanoma are rare and only few cases of melanoma metastases with simultaneous bilateral involvement of the inner ear have been reported.We report the case of DM, a 52 years old man, who was admitted to our department for a rapidly worsening sensorineural hearing loss with bilateral tinnitus and postural instability. Seven years before, the patient was diagnosed with a stage III-B melanoma of the trunk treated with surgical excision and axillary lymph-nodes dissection. The following oncological follow-up resulted negative. Vestibular evaluation excluded vestibular neuritis, revealing instead an horizontal nystagmus on the left side, alteration of the right orbicularis oculi muscle with minimal lagophthalmos and gait anomalies. The CT-scan excluded a stroke. The MRI showed bilateral enhancing lesions at IACs, thickened appearance at the right VIII cranial nerve level with hyperintensity of the signal and a similar lesion at D1 spine level. A debulking surgery and biopsy with translabyrinthine access were planned.The histological report showed a BRAF mutated melanoma and for that reason the patient was referred to the oncology department to start immunotherapy treatment.