Oropharyngeal mucosal malignant melanoma successfully treated with carbon ion radiotherapy: A case report

Abstract

　Mucosal malignant melanoma （MMM） is a rare disease with poor prognosis, and standard therapies have not been established. In recent years, the effects of carbon ion radiotherapy, molecularly targeted drugs, and immune checkpoint inhibitors have been verified. In this study, we present one case of oropharyngeal MMM, with central airway constriction, in which some foregoing treatments have been successful. A 55-year-old man complaining of swallowing pain and dyspnea was diagnosed with StageⅢ （T3N0M0） （AJCC/UICC, 7th edition）oropharyngeal MMM. There was no surgical indication, so he was sequentially treated with carbon ion radiotherapy, chemotherapy （DAV therapy）, and immunotherapy with ipilimumab （an anti-CTLA-4 antibody）. During the treatment period, the tumor size decreased, and we were able to continue and complete treatment without airway obstruction by using steroids. Good local control has continued for 3 years. Our conclusion is that a combination of carbon ion radiotherapy and drug therapy may be useful for MMM, and that steroids are helpful in preventing airway obstruction due to radiation therapy.