Melanoma - Oral Mucosal Lesion
They tend to be more aggressive than skin melanomas, behaving similarly to acral lentiginous melanoma of the skin. Most have a vertical growth (invasive) phase at the time of diagnosis and approximately 1/3 of patients give a history of a pre-existing pigmented lesion. Unlike melanomas of the skin, sunlight does not play an etiologic role. Only 10%-20% of patients survive five 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 African-American woman, 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 he/she 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 hemangiomas may grow rapidly and bleed but tends to not arise from a macule pigmented area.
- Kaposi sarcoma may appear similar; a biopsy differentiates between the two.