7. Premalignancy Flashcards
What are 3 factors of premalignancy?
Pathological features are not as severe as in cancer
There is risk of future transformation
There is no invasion
What does carcinoma in situ mean?
The tissue has transformed, and shows features of cancer throughout all the thickness of the tissue, but it is still not invasive.
What is the definition of invasive?
Cancer that has spread beyond the layer of tissue in which it has developed and is growing into surrounding, healthy tissues.
What is evidence for precancer?
- Precancerous lesions have undergone malignant changes during follow-up
- Red and white patches sometimes co-exist at the margins of OSCC.
- Precancerous lesions may share morphological and cytological changes observed in epithelial malignancies, but without frank invasion.
- Some chromosomal, genomic and molecular alterations found in oral cancers are also detected in precancer or premalignant phases.
What is the definition of premalignant condition 1978?
A generalised state associated with a significantly increased risk of cancer.
What is the definition of potentially malignant disorder 2005?
All clinical presentations that carry a risk of cancer
What is the definition of premalignant lesions?
A precancerous lesion is morphologically altered tissue in which oral cancer is more likely to develop than in its apparently normal counterpart.
What are 4 examples of premalignant lesions?
Erythroplakia
Leukoplakia
Palatal lesions in reverse smokers
Proliferative verrucous leukoplakia
What are 7 examples of premalignant conditions?
Oral submucous fibrosis
Actinic keratosis
Lichen planus
Discoid lupus erythematous
Sideropenic dysphagia
Hereditary epidermolysis bullosa
Xeroderma pigmentosum
Which layer does hypergranulosis occur in?
Granular cell layer
Which layer does hyperorthokeratosis occur in?
Stratum corneum
Which layer does hyperparakeratosis occur in?
Parakeratinised layer
What is the definition of epithelial dysplasia?
Cyto/histological changes within the epithelium which indicate a risk of malignant change.
What does epithelial dysplasia correlate with in premalignancy and malignancy?
Premalignancy- risk of transformation
Malignancy- prognosis
What are cellular dysplasia features to do with nucleus?
Nuclear pleomorphism
Anisonucleosis- variation nuclear size
Increased nuclear size
Increased number and size of nucleoli
Nuclear hyperchromatism
What are cellular dysplasia features to do with cells?
Cellular pleomorphism
Atyical mitotic figures
Anisocytosis- variation in cell size
What are architectural features of dysplasia to do with mitoses?
Increased mitoses
Superficial mitoses
Basal cell hyperplasia
What are architectural features of dysplasia?
Irregular epithelial stratification
Disturbed/loss of polarity
Drop shaped rete pegs
Premature keratinisation- dyskeratosis
Keratin pearls in rete ridges
What is mild dysplasia?
In lower third of epithelial thickness
What is moderate dysplasia?
Extends into the middle third, atypical changes more marked
What is severe dysplasia?
More than 2/3rd into epithelium, marked cytological atypia
What is low risk?
No, questionable, mild dysplasia
What is high risk?
Moderate to severe dysplasia
What are 4 factors affecting dysplasia?
Candida
Viral infections, eg. HPV
Tobacco
Alcohol
What are some differential diagnoses which may look like dysplasia?
Ulceration
Nutritional deficiencies such as iron, folate, B12
Trauma
Irradiation
Inflammation
What is leukoplakia?
Potentially malignant disorder
Term used to describe white plaque, excluding other known diseases or disorders that carry no increased risk for cancer
What are the 2 types of leukoplakia?
Homogenous- uniformly flat, thin, shallow cracks
Non-homogenous
What are the 3 types of non-homogenous leukoplakia?
Speckled- mixed red and predominantly white (erythroleukoplakia)
Nodular- small polypoid outgrowths rounded red or white excresences
Verrucous- wrinkled or corrugated appearance
What is erythroplakia?
A fiery red patch that cannot be characterised clinically or pathologically as any other definable disease.
What can erythroplakia look like?
Flat, smooth, granular or velvety surface
Why is erythroplakia red?
Due to epithelial atrophy (thinning) - epithelium becomes thinner so you can see the capillary bed underneath
How many cases does erythroplakia show dysplasia in?
40% of cases
What is reverse smoking palate lesions?
With the burning end of cigarette inside the mouth
Produces ulceration and damages the epithelium
Smoke carcinogens dissolve in saliva and reach the basal cell layer quicker
What is sublingual keratosis?
White patch on anterior floor of mouth and ventral surface of tongue with ebbing tide appearance
There is a high rate of transformation as thin epithelium at this location
What is oral submucous fibrosis?
Occurs in the mouth, pharynx and oesophagus
Stiffening of mucosa, fibrosis, blanched appearance, reduced mouth opening, deformed uvula
Associated with areca nut chewing
What is the histology of oral submucous fibrosis?
Hyalinisation of subepithelial connective tissue
Few fibroblasts
Narrow/obliterated blood vessels
Chronic inflammatory cells
Atrophic epithelium
How is areca nut eaten?
Areca nut and slaked lime wrapped in betel leaf and spices
Chewed and kept in vestibular sulcus
Adding tobacco increases risk
What does areca nut contain and how does it cause malignant changes?
Arecoline is hydrolysed by lime to produce arecaidine. Arecaidine is a carcinogen.
Arecoline induces fibroblast proliferation.
Flavonoids and tannins stabilise collagen.
It contains copper. Lysil oxidase is Copper dependent and cross links collagen.
What is actinic keratosis?
Important in development of SCC
Most common on lower lip
Causes dryness, atrophy, erythema, swelling, scaly lesions, blurring of vermillion demarcation, pallor areas
What is the histology of actinic keratosis?
Dysplasia
Acanthosis
Elastosis- increase in elastic fibres
Inflammatory infiltrate
Hyperplasia
What types of OLP are most premalignant?
Erosive
Atropic
What is dyskeratosis congenita>
Hereditary condition- most cases X-linked
Causes defective telomere maintenance
What are the features of dyskeratosis congenita?
White plaques on dorsal tongue, leukoplakia, abnormal skin pigmentation, nail dystrophy, pulmonary disease, malignancies
Where iWhat
