[Malignant melanoma of the mandibular gingiva]

The oral melanoma (OM) account for 1% of all melanomas. The prognosis is poor despite an adequate locoregional control of the disease.

A 47 year old women consulted for a blackish lesion of the mandibular gingiva next to tooth 37. Intraoral examination showed a dark pigmented lesion on the lingual side of the left mandibular molar region, extending from tooth 37 to the trine retro left molar. The biopsy confirmed the diagnosis of mucosal nodular melanoma. A wide surgical excision without ipsilateral neck dissection was performed. The treatment was completed by 30 Gy external beam radiotherapy, the patient died 18 months after the first consultation.

Oral melanomas have a poor prognosis probably because they are generally detected late. The most common sites for oral melanomas are the palate and maxillary gingival, malignant melanoma of the mandibular gingiva is extremely rare. About 30% of OM is preceded by areas of oral pigmentation for several months or years. The prognosis is poor with a 5% to 20% five-year survival rate.