Melanoma - Oral Mucosal Lesion
Melanoma is a rare malignancy of the oral cavity. It accounts for around 0.5% of all melanomas. Black individuals and individuals of Japanese descent are affected more often. There is a 2:1 male predilection, and most occur in the sixth decade of life or later.
Oral melanoma can present as a painless, bleeding mass or ulcer of the hard palate or maxillary gingiva, but about 60% of cases are asymptomatic and identified incidentally during a dental examination. It tends to be diagnosed when advanced, and only approximately one-third of patients give a history of a pre-existing pigmented lesion, either nevus or mucosal melanosis. The risk factors for oral melanoma are not well studied. Smoking, irritation from dentures, and alcohol use have been proposed but not confirmed as risk factors. Only around 10%-38% of patients survive 5 years or more.
Related topic: nail melanoma
C43.9 – Malignant melanoma of skin, unspecified
372244006 – Malignant melanoma
- Benign melanocytic nevus
- Amalgam tattoo (exogenous pigmentation) – This is the most common intraoral pigmented lesion. Usually the amalgam tattoo is not elevated and particles of dental amalgam (silver filling material) can often be detected on periapical radiographs of the lesional site.
- Melanotic macule / post-traumatic melanosis – These focal areas of melanin deposition could appear clinically identical to a junctional melanocytic nevus. Biopsy would be necessary to distinguish between the two.
- Melanoacanthoma – This uncommon condition occurs most frequently in young adult Black women, typically on the buccal mucosa. The lesion is generally much larger (1 cm or greater) than a melanocytic nevus, and it often follows a characteristic pattern of spontaneous involution over a period of days to weeks.
- Blue nevus is usually less than 1 cm in size and evenly pigmented.
- Physiologic pigmentation may appear ominous to a patient if they had not noticed the extensive pigmentation in the past. The pigment is even throughout and symmetric in distribution.
- Drug-induced pigmentation may have a sudden onset and rapid progression, but the pigment is even and there is no nodularity. This may be particularly concerning in patients infected with HIV.
- Lobular capillary hemangioma (pyogenic granuloma) may grow rapidly and bleed but tend to not arise from a macule pigmented area.
- Kaposi sarcoma may appear similar; a biopsy differentiates between the two.
- Oral squamous cell carcinoma
- Malignant salivary gland and soft tissue tumors