Oral Leukoplakia - Exodontia

Definition

The term leukoplakia (Greek, “white patch”) is defined by the World Health Organisation as “a white plaque / patch, firmly attached to the oral mucosa, that cannot be rubbed off or clinically identified as another named entity”. It is therefore strictly a clinical label rather than a histological diagnosis.

Leukoplakias should be biopsied, after which a more definitive diagnosis can be assigned. Most prove to be benign (usually hyperkeratosis or chronic inflammation), however, up to 20% may exhibit histological changes consistent with dysplasia or carcinoma. They should therefore be regarded with suspicion until proven otherwise, particularly if occurring in a high-risk site such as the ventral or lateral tongue or floor of mouth.

The clinical appearance is extremely variable with respect to size, shape, thickness, and homogeneity of colour. They are usually asymptomatic.

Photo of an Oral Leukoplakia

Photo of a Speckled Oral Leukoplakia

Ætiology

The exact ætiology remains unknown. Tobacco, alcohol, chronic local friction, betel use; sanguinarine use and Candida albicans are important predisposing factors. Others include Epstein Bar Virus and Syphilis. These latter carry a higher risk of malignant transformation.

Clinical Features

Occurs in approx 1% of the population; men > women

Three clinical varieties are recognised:

homogeneous (common; faintly white – very thick & opaque)
speckled (less common; non-homogenous / heterogenous leukoplakias has a high risk of malignant transformation) and
verrucous (rare).

The buccal mucosæ, tongue, floor of the mouth, gingivæ and lower lip are the most commonly affected sites. However, leukoplakias found in the soft palate complex, on ventro-lateral aspects of the tongue & the floor of mouth have a high risk of malignant transformation. The malignant potential depends on appearance, site & some ætiological factors.

Laboratory Tests

Histo-pathological examination.

Photo of a Verrucous Oral Leukoplakia

Differential Diagnosis

The following conditions should be considered before making a diagnosis of leukoplakia:

Lichen Planus
Cinnamon Contact Stomatitis
Candidiasis
Hairy Leukoplakia
Lichenoid reactions
Chronic biting
Smokers Keratosis
Leukœdema
Chemical burn (such as Aspirin)
Uræmic Stomatitis
Skin graft and
Discoid Lupus Erythematosus.

Treatment

Elimination or discontinuation of pre-disposing factors (such as tobacco or betel nut)
Surgical excision is the treatment of choice
Medical treatment entails the use of anti-inflammatories or anti fungals; topical anti-cancer drugs or retinoid compounds. These cause regression of the leukoplakias but their efficacy is temporary.
Chemo-prevention, which prevents leukoplakias from becoming malignant, entail the use of retinoids (such as 13-cis-retinoic acid and fenretinide). However, problems with side-effects, lack of availability and recurrence limits their use.
Lesions removed followed by regular follow-ups.