Oral premalignant lesions: leukoplakia and erythroplakia
- Topic
White or red patches in the mouth that do not rub off and have no other cause can turn into cancer and must be biopsied.
What it is
Oral potentially malignant disorders are lesions in which mouth cancer is more likely to develop than in normal mucosa. Leukoplakia is a white patch or plaque that cannot be classified as any other definable lesion: it is a diagnosis of exclusion. Erythroplakia is a red, velvety patch; it is rarer but has the highest rate of malignant change of all oral precancerous lesions. Both are strongly linked to tobacco and alcohol.
White and red oral lesions: telling them apart
| Lesion | Key feature | What to do |
|---|---|---|
| Pseudomembranous candidiasis | White plaques that wipe off, leaving a red base | Antifungal; recheck |
| Frictional keratosis | White patch next to a sharp tooth or denture | Remove the cause; recheck in two weeks |
| Leukoplakia | White patch that does not wipe off and has no other cause | Biopsy; stop tobacco and alcohol |
| Erythroplakia | Red, velvety patch, often on soft palate, floor of mouth or cheek | Biopsy and excision |
| Oral carcinoma | Ulcer or lump that persists, may bleed or be indurated | Urgent referral |
In clinical practice
- Patches on the floor of the mouth and the lateral and ventral tongue deserve particular attention because these are frequent sites of oral cancer.
- A lesion that seems to improve after removing a cause must still be rechecked until it disappears.
Next step / Initial management
- Examine the whole mouth, document size, colour and site (a photo helps follow-up) and look for a removable cause: candidiasis, sharp tooth, ill-fitting denture.
- Treat a removable cause (antifungal for candidiasis, dental correction) and recheck in about two weeks; a patch that persists needs biopsy.
- Advise stopping tobacco in all forms and alcohol; this is part of treatment.
- Refer to oral surgery, maxillofacial surgery or otolaryngology for biopsy: urgently (within two weeks) for any red patch, mixed red-white patch, ulcer, induration or a patch that persists after removing the cause.
- After diagnosis, follow-up is long term because the risk of cancer remains.
Test yourself
Think of the answer, then tap the question to see it.
Why is oral leukoplakia called a diagnosis of exclusion?
Because it is defined as a white patch that cannot be classified as any other definable lesion; candidiasis, friction and other causes must be ruled out first.
Which oral premalignant lesion has the highest risk of malignant transformation?
Erythroplakia, the red velvety patch; many already show carcinoma in situ or invasive carcinoma when first biopsied.
A smoker has a white patch on the side of the tongue that does not wipe off and persists after smoothing a sharp tooth. Next step?
Biopsy, through referral to oral or maxillofacial surgery or otolaryngology, plus advice to stop tobacco and alcohol.
Connections
Educational content; it does not replace a medical assessment and is not a clinical instruction. For a real case, follow current guidelines and specialist advice.
Sources: Oral Leukoplakia (StatPearls (NCBI Bookshelf), 2023); Oral erythroplakia: a review (Oral Oncology) (PubMed, US National Library of Medicine, 2005); Oral Cancer (National Institute of Dental and Craniofacial Research (NIH), 2024); Tongue Cancer (StatPearls (NCBI Bookshelf), 2023).
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Representative model, for educational purposes only.