A clinical study of 10 cases of malignant melanoma arising in the oral cavity

Oral malignant melanomas were clinically studied in 10 patients treated at the Department of Oral and Maxillofacial Surgery If, Osaka University Graduate School of Dentistry, and the Departments of Dentistry and Oral Surgery, of Tenri Hospital and of Higashiosaka City General Hospital from 1987 through 2003. The subjects were 9 men and 1 woman aged from 43 to 82 years. The tumor location was the maxillary gingiva in 5 patients, the hard palate in 2, the lower gingiva in 2, and the buccal mucosa in 1. Two patients were in Stage I, 7 in Stage II, and 1 in Stage III. As for the histological invasion grade, 1 patient was in Level I, 3 in Level II, and 4 in Level III. Tumors were removed surgically in 8 patients, 6 of whom received chemotherapy after operation. The other 2 patients received either carbon ion radiotherapy or chemotherapy alone. Six patients died of distant metastasis. Distant metastasis occurred frequently in patients with deeply infiltrating tumors and/or multiple cervical metastatic lymph nodes. The histological invasion level and the number of metastatic regional lymph nodes may be useful for predicting the outcomes of patients with oral malignant melanoma.