Pigmented Lesions of the Mouth

Pigmentation in the mouth may present as brown/ black or purple/ red in colour. The most sinister of these is malignant melanoma. It is therefore important to distinguish this from the other causes of oral pigmentation.

Brown or black lesions

¨ Malignant melanoma (see below)

¨ Pigmented naevi (uniform colouration)

¨ Amalgam tattoo

¨ Addison’s disease (increased ACTH produced)

¨ Peutz-Jegher syndrome (peri-oral freckles, intestinal polyps)

¨ Racial pigmentation

¨ Lichen planus (rare)

¨ Smokers Melanosis (caused by local irritation)

¨ Pregnancy, oral contraceptive pill

 

Purple or red lesions

¨ Amelanotic melanomas

¨ Erythroplasia (see below)

¨ Haemangiomas (Blanch under pressure)

¨ Kaposi’s sarcoma (HHV8, proliferation of endothelial cells)

¨ Squamous carcinoma

¨ Purpura

¨ Other blood blisters – vesiculobullous lesions

¨ Telangiectases (eg HHT)

¨ Lingual varices

¨ Pyogenic granuloma

¨ Pregnancy epulis

¨ Giant cell epulis

¨ Geographical tongue (see below + picture opposite)

¨ Erythematous candidosis

¨ Median rhomboid glossitis

¨ Denture-related stomatitis

¨ Trauma

 

 

Malignant Meanoma

Intraoral melanomas are rare. Most patient are between 40—60 years of age,  M:F 2:1.

An area of mucosal pigmentation, usually dark brown/ black, or red if non-pigmented.  Sometimes with satellite pigmented spots. The lesion may bleed or ulcerate.  Typically firm and rubbery, with a raised irregular outline.  Usually on the hard palate or maxillary gingival/alveolar ridge. Varies in size from a few millimeters to > 1 cm diameter.  Usually macular or nodular.

Any hyperpigmented oral lesion with irregular margins or a history of growth should be treated with suspicion. Early biopsy is essential. The prognosis of intraoral melanomas is poor as they are often missed until there are symptoms or lymph node involvement. Distant spread to the lungs, liver, bones and other organs.

Treatment is by radical excision and usually chemotherapy or radiotherapy, or both. It has a poor prognosis. Median survival for mucosal melanomas is less than 2 years, 5 year survival rate of approximately

Erythroplasia/Erythroplakia

Rare condition – bright velvety plaques, mainly in elderly males

Much more likely to undergo malignant transformation (85%)

Most commonly seen on soft palate, FOM, buccal mucosa

Can be associated with white patches – then a speckled leukoplakia (see picture)

Biopsy essential to ascertain degree of epithelial dysplasia, and exclude diagnosis of carcinoma

Stop causal factors, remove lesions and follow-up closely

 

Geographic Tongue (Erythema Migrans)

¨ 1-2%, causes sore tongue – although often asymptomatic,

¨ Genetic – family Hx, associated with psoriasis in 4% of cases

¨ Typically involves dorsum of tongue, sometimes the ventrum

¨ Irregular, pink/red depapillated areas often surrounded by distinct yellowish slightly raised margins,  changes in shape/size/location

¨ Diagnosis mainly clinical, but blood examination necessary to exclude diabetes, anaemia