Abstract
Malignant melanoma is a malignant tumor derived from melanocytes, and typically occurs in the skin. Malignant mucosal melanoma rarely arises in the oral cavity, accounting for 0.5％ of all malignant melanomas. Amelanotic malignant melanoma lacking melanin pigment accounts for 2.0％ of malignant mucosal melanomas in the oral region. Here, we describe a patient who exhibited amelanotic malignant melanoma in the maxillary gingiva and palate.
A 64-year-old woman was referred to our department for examination and treatment of a nodular lesion in the right maxillary gingiva in February 2018. At the initial visit, a nodular lesion measuring 60×45mm was observed in the right maxillary gingiva. A biopsy was performed on the lesion, and histopathological evaluation yielded a diagnosis of amelanotic malignant melanoma. On preoperative analysis, the lesion was classified as cT4aN0M0, so we performed right maxillectomy. Postoperative histopathological analyses identified the tissue as an amelanotic malignant melanoma with venous and lymphatic invasion. Therefore, postoperative adjuvant therapy was planned. However, adjuvant therapy could not be performed in this case for economic reasons and because the patient did not consent to further treatment. Metastasis in the small intestine occurred 1 year postoperatively, and the patient died 6 months later.
