Oral malignant melanoma detected after resection of amelanotic pulmonary metastasis

INTRODUCTIONSolitary pulmonary metastasis from oral malignant melanoma is very rare.PRESENTATION OF CASEWe demonstrated a 84-year-old patient with a lung nodule that was diagnosed as malignant melanoma by video-assisted thoracoscopic resection. Because primary pulmonary malignant melanoma was extremely rare, the tumor was thought to be a metastasized from an occult primary lesion. A detailed physical examination revealed a black tumor in the oral cavity, and this was suspected to have been the primary. Resection of the hard palate tumor and dissection of the cervical lymph nodes were performed. The patient was simply followed up without further therapy at his request, and he died one year after surgery due to bleeding from a pleural metastasis of malignant melanoma.DISCUSSIONPrimary melanoma of the oral cavity is rare, accounts for 0.5% of all oral cancers, and 0.8–1.8% of all melanomas. Because of absence of symptoms in the early stage of the disease and the presence of the tumor in relatively obscure areas of the oral cavity, the diagnosis is unfortunately often delayed. In view of the rarity of primary lung melanoma, when lung tumor was diagnosed as malignant melanoma, detailed physical examination of the entire skin and mucosa including the oral cavity was necessary.CONCLUSIONOral malignant melanoma was very rare, but oral cavity should be examined when the pulmonary nodule was diagnosed as malignant melanoma.