Clinical patterns and outcomes of patients affected by primary malignant melanoma of the oral mucosa: A European multicenter retrospective chart review

Introduction: The purpose of this European multicenter study was to describe and assess the characteristics, diagnosis, management, and recurrence of oral malignant melanoma at different European oral and maxillofacial surgery centers. Materials and methods: This study was based on a systematic computer-assisted database that allowed the recording of data for all primary oral mucosal melanomas treated in the involved surgical units across Europe between January 1, 2003 and December 31, 2022. The following data were recorded for each patient: gender, age, site, TNM staging, metastases, symptoms, imaging features, histopathological features, treatment, complications, recurrence, follow up, and survival. Results: A total of 29 patients (15 females, 14 males) with a primary oral mucosal malignant melanoma fulfilled the inclusion criteria. The mean age was 64.4 years. The most frequent primary site was the vestibular and crestal maxillary gum. Nineteen patients had been diagnosed with a T3 oral melanoma, nine patients with a T4a oral melanoma, and one patient with a T4b neoplasm. Three patients had distant metastases at diagnosis. Clinically, the most frequently observed clinical features were hyperpigmentation, nodular appearance, ulceration, and hemorrhage. Among the 27 surgical cases, radical/clear margins were obtained in 24 cases, non-radical/invaded margins were obtained in two cases, while in one case a non-specific result of margin positivity was found. The overall 2-year survival was 62%. The 2-year disease-free survival was 52%. Conclusions: Oral mucosal melanoma is an aggressive and often asymptomatic malignancy. The overall long-term survival for patients with oral mucosal melanoma is poor, with a high rate of distant metastasis, independently from the performed treatment. Prevention and early diagnosis could be crucial to improving the disease-free survival of patients with oral mucosal melanomas.