Potentially malignant lesions and oral cancer Flashcards Preview

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Flashcards in Potentially malignant lesions and oral cancer Deck (38)
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1

What does the histology of the oral epithelium look like?

2

What are the potentially malignant conditions of the oral cavity?

• Leukoplakia

•    Proliferative verrucous leukoplakia

• Erythroplakia

•    Oral lichen planus

•    Oral submucous fibrosis

•    Actinic Cheilitis (lip only)

•    Palatal lesion of reverse cigar smoking

•    Discoid lupus erythematosus

•    Hereditary disorders eg dyskeratosis congenita

3

What is this?

Leukoplakia: any white lesion that cannot be identified either pathologically or clinically and is not related to physical or chemical causes other than smoking.

4

What is the clinical classification of leukoplakia?

HOMOGENEOUS: a predominantly white leukoplakia of generally uniform appearance and texture even though surface irregularities may be present

•NON-HOMOGENEOUS: either a predominantly white

or

•ERYTHROLEUKOPLAKIA: white and red lesion with an irregular texture throughout. Lifetime risk of transformation to OSCC is much higher compared to homogenous leukoplakia.

5

What is this?

Extensive leukoplakia.

6

What are the stats for leukoplakia?

•    Leukoplakia has

•    Seen in 1-5% of population

•    < 2% OPMD progress to cancer each year

•    Tongue, FOM, retro molar, soft palate are higher risk vs other intraoral sites

7

What factors would increase the risk profile of a Leukoplakia?

•High risk sites for oral cancer such as floor of mouth and lateral aspect of the tongue.

•Non homogenous texture (non homogenous leukoplakia)

•Mixed red and white non homogenous areas. (erythroleukoplakia)

•Raised compared to surrounding mucosa. •Induration at base of leukoplakia and

surrounding tissues.

•Verrucous (rough, “rugpile like”) surface. •Presence of ulceration.

•    Absence of tobacco use to account for leukoplakia increases risk

•    Age: older patients more at risk.

•    Sex: female patients more at risk.

• Smoking

8

What is the risk of malignant transformation depending on the degree of dysplasia?

None = 1%

Mild (1/3rd of epithelium dysplastic) = 5%

Moderate (1/2 to 2/3rds) = 15%

Severe (top to bottom of epithelium) = 25%

9

What is dysplasia?

It can be seen down the microscope and is the amount of 'disorder' of cells and disruption of cell layers. There are three categories:

-dysplasia of the epithelial architecture

-cytological features of dysplasia

-functional aspects of dysplasia 

You can get basal cell hyperplasia which is when the basal cell layer thickens and goes up into the stratume spinosum (prickle cell layer) and down into the connective tissue (creating drop shaped rete ridges). Does NOT break throught the basement membrane though, if it does the invasion becomes malignant (no longer termed dysplastic). 

In dysplasia you also get loss of polarity of cells, the cell nuclei move away from the basement membrane and towards the stratum spinosum (prickle cell layer). Also get darkening of the cells (change in colour on histology slide). 

10

What is the cytology of dysplasia?

•    Pleomorphic cells

•    Increase in cell size

•    Loss of polarity

•    Loss of intercellular adhesion

•    Nuclear pleomorphism and hyperchromatism

•    High nucleus : cytoplasm

•    Prominent nucleoli

11

What are the functional aspects of dysplasia?

• Mitotic figures:

- increased frequency

- mitoses in suprabasal

- abnormal forms

• Aberrantkeratinisation:

- dyskeratosis (keratin production in epithelial layer normally just on the outside surface, in dyskeratosis keratin is seen anywhere in the epithelial layer. This indicates it's more likely to be malignant.)

12

What is this?

Normal epithelia

13

What is this?

Keratosis/hyperplasia

14

What is this?

Mild dysplasia

15

What is this?

Moderate dysplasia

16

What is this?

Severe dysplasia

17

What did the Cochrane review of Leukoplakia show in 2008?

•    No evidence to suggest that any medical treatment has any effect on outcome.

•    Some evidence’ for vitamin A, retinoids, beta carotene & lycopene - may resolve lesions but no evidence for increased survival, and evidence is very limited

 

18

What have the WHO collaborating Centre for oral cancer and precancer in the UK working group said?

• There are no good studies that show stopping smoking or alcohol improves outcomes

• There is no evidence for medical treatment of dysplasia or leukoplakia

• 40% OPMD’s will regress over time, especially in non-smokers

19

What is the evidence for surgical intervention?

•    Cochrane review Leukoplakia 2008‘Surgical Rx no RCT’s, small observational studies show conflicting results

•    Meta- analysis of oral dysplasia recommends surgical excision of high grade dysplastic lesions. Mehanna et al, 2009

20

When is surgical treatment of leukoplakia considered?

For management of severely dysplastic or carcinomatous lesions.

Advantages: entire lesion for histopathological examination

Disadvantages: surgical removal is associated with morbidity & leukoplakia as entity overall has a low transformation rate!

21

What is the follow up for leukoplakia?

•Mild or moderately dysplastic lesions may be treated more conservatively by removing predisposing factors (ie stopping smoking or drinking excess alcohol).
•Lesions are usually biopsied periodically to exclude progression.
•As only approximately a third of all leukoplakias that will transform into OSCC do so in the first 2 years, long term follow up is indicated.
•Periodic re-biopsy is integral to long term follow up especially if there are any morphological changes of concern.

22

What is erthoplakia?

•Erythoplakia refers to a red patch which cannot be identified clinically or histologically as any other disease.

•Rare •Associated with a high rate of malignant transformation.

•Biopsy is mandatory and often multiple biopsies are taken (field mapping biopsy).

•Histopathological examination often reveals dysplasia or carcinoma.

23

What did Van der Waal say about erythroplakia in 2010?

• Erythroplakia is all ‘moderate to severe dysplasia’ on biopsy

• The ‘vast majority’ will undergo malignant transformation

• No case series large enough to give accurate numbers

• Advise excising all erythroplakia

24

What is the management of erythroplakia?

•    In general terms, in view of the high risk of these lesions, surgical excision is considered preferable to more conservative management.

•    The management is generally dictated by clinical and especially histopathological findings with excision of the lesion considered if severe dysplasia is noted. If there is carcinoma present histopathologically then management will be identical to that of an OSCC.

•    Regular follow up is necessary as these lesions have a high rate of subsequent malignant transformation even after surgery and the patient is at a significant risk of developing a secondary primary tumour.

25

What is this?

Proliferative verrucous leukoplakia (PVL).

•    A variant of leukoplakia

•    Rough, irregular surface which slowly expands.

•    Other similar lesions may occur simultaneously and coalesce to form a large leukoplakia.

•    Transformation into verrucous OSCC occurs inevitably as nearly all cases unrelentingly move towards malignancy

26

What is this?

Chronic Hyperplastic Candidosis.

1 in 10 Candida infections turn into this.

27

What is this?

Oral submucous fibrosis.

• Often seen in India(particularly south)

• Palateandbuccal mucosa appear white

•A progressive inflammation resulting in fibrotic change of the oral mucosa and orophoraynx.

•Decrease in mouth opening

•Possible later involvement of swallowing and speech

•A “ leather like” feel due to the increased stiffness and bands of scar like tissue.

•The pathophysiology is thought to be related to habits such as use of betel and areca nut , lime, tobacco and hypersensitivity to certain foods such as chilli.

•OSMF is considered a potentially malignant lesion •Need for long term follow up.

28

What is this?

Discoid Lupus Erythematosus (DLE)

•    There is some controversy as to whether DLE oral lesions have a premalignancy risk

29

What is this?

Actinic Cheilitis (AC)

•    2.5 times higher malignant transformation of solar cheilosis compared with skin actinic keratosis

-affects people who spend a long time in the sun

 

30

What are some stats about oral cancer?

•    9 in 10 are Oral Squamous Cell Carcinoma

•    1 in 10 are minor salivary gland tumours, lymphomas & malignant melanoma