An unusual case: malignant melanoma in the oral cavity

Malignant melanoma in the oral cavity is rare, with uncertain etiology, possibly associated with pre-existing melanosis, dental irritation, cigarette smoking, alcohol use, and formaldehyde exposure. A 59-year-old white female complained of a darkened lesion that appeared 7 years ago, which increased after the lower first molar extraction. Intraorally, a 2 cm darkened lesion with irregular borders and irregular surface was identified on the lower right alveolar ridge. Radiographically, a radiolucent image compatible with a tooth socket after extraction was observed. The incisional biopsy and microscopic analysis revealed the proliferation of atypical melanocytes with neoplastic characteristics invading the connective tissue arranged in sheets and cords depositing brownish pigment, consistent with melanin. The final diagnosis was malignant melanoma. The patient underwent surgical treatment with follow-up. Although rare, malignant oral melanoma should be considered as a differential diagnosis for blackened patches in the oral cavity.