Tumor size and depth in primary malignant melanoma in the oral cavity influences survival

Abstract

Purpose: Primary oral malignant melanoma (OMM) is rare, and there are few studies examining the impact of this disease. This study aims to assess the outcome of surgically treated patients with OMM treated at a single institution.

Patients and methods: Ten patients with OMM treated at the Department of Oral and Maxillofacial Surgery, Ruhr-University Bochum, Bochum, Germany, between 1992 and 2002 were analyzed retrospectively. Treatment included wide local excision with or without modified neck dissection, supplemented by radiotherapy and chemotherapy. Clinical and histologic data were analyzed by univariate analysis.

Results: Five patients were diagnosed with stage I disease, 4 with stage II disease, and 1 with stage III disease at presentation. The alveolar arch (40%) and palate (30%) were the most frequently affected sites. The adjusted hazard ratio was 4.513 (95% confidence interval, 1.47-13.89) for size and 1.919 (95% confidence interval, 1.03-3.59) for depth, yielding a poor prognosis (P = .009 and P = .048, respectively). The mean survival rate of the patients succumbing to disease was 19 +/- 17 months.

Conclusions: Primary OMM carries a poor prognosis. Early identification of OMM and its treatment by radical surgery comprise the single most important treatment strategy. Any pigmented lesion in the oral cavity not clearly clinically amenable to diagnosis should be excised for histologic confirmation. Analysis of the lymph node status, supplemented by sonography or other imaging, and postoperative histologic evaluation of the size and depth should be performed routinely. In cases in which the mucosal melanoma may not be the primary site, all potential primary sites should be examined.