Remission of Mucosal Melanoma of the Middle Ear and Petrous Temporal Bone and Reversal of Cranial Nerve Paresis Following Radiation and Single Agent Nivolumab: Clinical Capsule and Review of the Literature

Objective: We report disease remission and recovery of fifth and seventh nerve paresis in a case of primary mucosal melanoma of the middle ear and petrous temporal bone. Patient: A 74-year-old man developed sudden, profound, right sided sensorineural hearing loss, disequilibrium, otalgia, and cranial nerve V and VII dysfunction. Imaging demonstrated an unresectable, osteolytic lesion involving the middle ear and anterior petrous apex. Melanoma was diagnosed via in-office biopsy; whole-body metabolic imaging revealed no other primary site. Intervention: Multidisciplinary management included radiation therapy (30 Gy, 10 fractions) followed by induction (five cycles, q2w) and maintenance nivolumab (six cycles, q3w). Main Outcome Measure: Complete metabolic response of primary site and metastases on imaging, recovery of cranial neuropathies. Results: Following palliative radiation therapy and induction nivolumab, cranial neuropathies resolved. With maintenance-dose nivolumab, primary site and metastases exhibited a complete response. Therapy was stopped at 16 months post-diagnosis. Complete remission was maintained until 22 months after diagnosis. The patient developed a solitary cerebral metastasis which was refractory to radiosurgery and biopsy confirmed melanoma. He expired 2 years, 8 months post-diagnosis. Conclusions: Mucosal melanoma of the middle ear and petrous temporal bone is exceedingly rare. Management is individualized and surgery is undertaken when possible. Key observations in this case are the complete metabolic response and reversal of cranial nerve neuropathies following radiation and anti-programed cell death receptor ligand 1 therapy. Non-surgical treatment is worthy of study as initial management for similar lesions.