Pre-Malignant Lesions

Most oral cancers appear to arise in ‘normal’ oral mucosa but some are preceded by potentially malignant / pre-malignant clinically obvious lesions.

These include:

Actinic Cheilitis
Erythroplakia / Erythroplasia (Red Patch)
Leukoplakia (White Patch)
Speckled Leukoplakia
Verrucous Leukoplakia

Conditions that MAY predispose to malignancy (ie oral cancer) include:

Lichenoid lesions + Lichenoid Dysplasia
Sub-Mucous Fibrosis
Previous oral malignancy
Syphilitic Leukoplakia / Glossitis
Immunosupression
Dyskeratosis Congenita
Paterson-Kelly syndrome
Discoid Lupus Erythematosis

What are thought to be the lesions / conditions likely to cause malignancy are logically the same ones that cause pre-malignancy.

Potentially_Malignant_Oral_Lesions-1015x797

Actinic Cheilitis (AKA Actinic Keratosis of Lip, Solar Keratosis, Solar Cheilosis)

Occurs in adults & mainly men
Mainly seen in persons from the Tropics
Chronic pre-malignant keratosis of the lip caused by long exposure to solar irradiation. Most is seen:
- on the lower lip with sparing of the commissures
- in fair-skinned men
- 4 – 8th decade of life
- outdoor jobs / activities
Early stages – erythema & œdema; later stages, the lip becomes dry, scaly & wrinkled with grey / white changes in pigmentation. Lesions appear as a smooth or scaly, friable patch or even the whole lip. Later still, the lip becomes thickened with small greyish-white plaques with even warty nodules forming
Prevention with sunblocks
Treatment with topical chemo-exfoliants & surgery

Erythroplasia / Erythroplakia (AKA Red Patch)

Occurs in the middle aged & the elderly & mainly in men
Less common than leukoplakia
Erythroplakia contains areas of dysplasia, carcinoma in situ or invasive carcinoma in virtually every case

Most potentially malignant of all oral mucosal lesions.

Red velvety patch of variable configuration, usually level / depressed with surrounding mucosa, commonly on the soft palate, floor of mouth or the buccal mucosæ
Some erythroplakias are associated with white patches & hence termed, speckled leukoplakias
Any causal factor, such as tobacco, should be stopped
Lesions removed followed by regular follow-ups

Leukoplakia (AKA White Patch)

Occurs in approx 1% of the population; men > women
Predisposing habits – tobacco, alcohol & betel use; sanguinarine use
Leukoplakia has a wide range of clinical presentations, from homogenous white plaques (faintly white – very thick & opaque) to nodular white lesions to lesions admixed with red lesions.

The malignant potential depends on appearance, site & some ætiological factors.

Appearance – non-homogenous / heterogenous leukoplakias has a high risk of malignant transformation
Site – soft palate complex, ventro-lateral tongue & FOM have a high risk of malignant transformation
Ætiology – virus (HPV, EBV), bacterial (syphilis) or fungal (Candida) have a high risk of malignant transformation
Any causal factor, such as tobacco, should be stopped.
Lesions removed followed by regular follow-ups.
Surgical / Medical treatment

Photo of Speckled Leukoplakia (arrowed)

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Dysplasia seems to be the most predictive marker in use for malignant potential.

Factors Predictive of Future Malignant Transformation may include:

History of cancer of upper aero-digestive tract
Expression of P53 tumour suppressor protein
Changes involving chromosomes 3p or 9p; “Loss of Heterozygosity” LOH
Chromosomal polysomy

Principles of Management of Dysplastic Lesions:

Stop any associated habits, eg betel quid or smoking
Treat any candidal infection and / or iron deficiency if present
Biopsy to assess dysplasia
Assess risk of pre-malignant change on clinical & histological findings
Consider ablation of individual lesions
Maintain observation for signs of malignant change

Options for the Management of Pre-Malignant Lesions:

Observation for early detection of cancer
Surgical excision with grafting (if required)
Cryotherapy
Laser excision / vaporisation
Topical chemotherapy (eg bleomycin)
Retinoids

Cryotherapy heals rapidly to leave an apparently normal mucosa. However, there is some uncertainty about the risk of OSCC subsequently arising in these sites.

With laser ablation, seemingly similar concerns.

Topical chemotherapy are largely ineffective and lesions that resolve, recur on cessation of the drugs.