Mucosal Melanoma: A Rare Entity and Review of the Literature.

Mucosal melanoma is a rare variant of melanoma representing around 1% of total cases of melanoma diagnosed. The usual sites of mucosal involvement are the sino-nasal passages, the oral cavity, and less commonly the upper gastrointestinal (GI) tract. It also has been reported to occur in vulvovaginal and anorectal mucosa.  We present a rare case of mucosal melanoma that presented as recurrent epistaxis, headache, and sinus pressure. CT maxillofacial imaging revealed a large mass right nasal cavity. This was biopsied by ENT and shown to be mucosal melanoma. This was treated with palliative radiation followed by immunotherapy with nivolumab.  Along with details of the case, we also discuss current treatment options with a focus on the role of immunotherapy and its efficacy in cases of head and neck mucosal melanoma. Our review of literature supports use of combination immunotherapy (including both nivolumab and ipilimumab) as it shows greater efficacy than either therapy alone. When combined with radiation therapy (RT) the overall response rate is improved and RT induces an abscopal effect; where benefits of RT are also seen at nonirradiated locations.  In our patient, the use of radiation was essentially palliative as the patient was deemed to not be a surgical candidate. We discuss in our literature review the optimum timing of radiation in relation to definitive surgery or immunotherapy.