Oral Premalignant Lesions Flashcards
What is Erythroplakia
A predominantly red lesion of the oral mucosa that cannot be characterised clinically or pathologically as any other definable lesion
What is leukoplakia
- A white patch/plaque of questionable risk having excluded other diseases or disorders that carry no increased risk of cancer
- Biopsy mandatory
- Clinical term but no specific histology
What is a precursor lesion
Any identifiable or altered mucosa with a risk of transformation
Relatively non-specific term
What coloured lesion carries the lowest and the highest cancer risk
- Oral white lesions have the lower risk of malignant transformation
- Red and speckled lesions have the highest risk
- But there are completely benign white and red lesions
Which oral cancers are classified into lesions and which are classified into conditions
- In reality these overlap
- Lesions: leukoplakia, erythroplakia, palatal changes in reverse smoker
- Conditions: oral sub mucous fibrosis, lichen planus, discoid lupus eruthematosus, dyskeratosis congenita, syphilis
What are potentially malignant disorders thought to be a result from
- Field change or field cancerisation
- Process whereby a wide area of tissue undergoes genetic alterations or chromosomal changes, making it prone to developing cancer anywhere within the field (often never undergoes malignant transformation and is not known how many OPMDs develop into oral cancers)
- The changes may be visible or often not visible
Why do different parts of the field change have different risks of developing into cancer
There are overlapping areas of slightly different changes making up the field
Each patchy is a clone of cells that has a survival advantage over normal cells
Clinical and histological visibility depends on which genes are affected
Therefore different parts have different risks for developing into cancer
What are the implications of the extent and size of field change? And is the patient at risk of more than one type of cancer?
- The extent of the field may or may not be visible clinically or histologically, meaning the size of the field at risk cannot easily be determined
- The size of the field affects the success of surgical treatment because excision could only be effective for a small field
- Pts are at risk of multiple potentially malignant lesions and cancers in different sites in the field
What is dysplasia a feature of and is it seen in a field change?
- Histological feature of pre-malignancy = best predictor of risk and indicator of future transformation
(but non-dysplastic lesions can transform too) - May or may not be seen in all field change
What are the aetiological factors of OPMDs?
- Tobacco, alcohol, betal quid, other habits
- Genertic, idiopathic/autoimmune, candidal infection, HPV?, nutrition?
What are the risk factors for OPMDs?
- More men than women
- Aged over 40
- Smokers and heavy drinkers
What is the definition and what are the clinical features of erythroplakia?
- Fiery red patch of the oral mucosa that cannot be characterised clinically or pathologically as any other definable disease
- Common sites: FOM, lateral and ventral tongue and soft palate
- Features: Surface is velvety and ranges from dull matte red to bright scarlet. Lesion often flat or slightly depressed. Epithelium is atrophic and non-keratinised
- Affects: smokers and elderly
What is the malignant transformation risk for erythroplakia?
- Highest risk of malignant transformation
- Annual transformation rate of ~1%
- ~50% of lesions turn out to be malignant on first biopsy, and the remainder show some degree of dysplasia, often severe
What is the differential diagnosis for Erythroplakia?
Desquamative gingivitis, erythematous lichen planus, discoid lupus erythematous, pemphigoid, hypersensitivity reactions, Reiter’s disease, erythematous candidiasis, histoplasmosis, haemangioma, Kaposi’s sarcoma
What are the steps for diagnosis of red patch
- Exclude other known conditions, disorders, diseases based on history and examination
- Provisional clinical diagnosis of erythroplakia
- Biopsy: gives diagnosis of erythroplakia without dysplasia or erythroplakia with dysplasia. Or confirms other known disorder
What is the definition and how common is leukoplakia?
- White patch of questionable risk having excluded other known disease or disorders that carry no increased risk for cancer (a clinical term and has no specific histology)
- Common: accounts for over 3/4 of all potentially malignant disorders and is found in 1-5% of the population
What are the clinical types of leukoplakia and what are the clinical features of each?
- Homogenous - lesions are uniformly flat, thin and exhibit shallow cracks of the surface keratin
- Non-homogenous - speckled, nodular, verrucous, proliferative verrucous
What are the general clinical features of leukoplakia? what is the transformation rate?
- Common sites: posterior buccal mucosa, retromolar region, FOM, tongue
- Features: No specific clinical appearance but are tough and adherent white patches
- Relatively low transformation rate (but greater risk than oral LP)
- Risk of transformation:
1. severe dysplasia
2. nodular/verrucous surface greater risk than flat
3. Large patches
4. Lesions on lateral/ventral tongue and FOM
5. Lesions in older pts