Potentially Malignant Disorders And Oral Cancer

Question 1

Define potentially malignant lesion

Answer 1

Altered tissue in which cancer is more likely to form

Question 2

Define potentially malignant CONDITION

Answer 2

Generalised state with increased cancer risk

Question 3

Give some potentially malignant conditions

Answer 3

Lichen planus

Iron deficiency - reduced barrier to carcinogen so more oxidative stress and free radical production

Tertiary syphillis

Question 4

Give some potentially malignant LESIONS

Answer 4

Erythroplakia

Leukoplakia
- CHC
- proliferaitve verrucous leukoplakia

Question 5

What is CHC?

Answer 5

Variant of oral candidiasis

• often occurs at commissures of mouth
• often found in smokers
• dysplasia may be present

Question 6

How can CHC be shown histopathologically?

Answer 6

PAS (periodic Schiff stain)

• highlights candidal hyphae on staining
• shows prescence of C.albicans

Question 7

Tx of CHC?

Answer 7

Systemic antifungal
- fluconazole, 14 days

Biopsy

stop smoking

Question 8

What clinical predictors may indicate malignancy in leukoplakia?

Answer 8

Age and gender of pt

Idiopathic cause

High risk site
- FOM and tongue

Clinical appearance
- non homogenous, verrucous, ulcerated or Leuko-erythroplakia

Question 9

Biggest predictors for malignant change histopathologically?

Answer 9

Dysplasia

Atrophy

Candida infection

Question 10

What is dysplasia?

Answer 10

Disordered maturation (growth) in a tissue

Question 11

What is cellular atypica?

Answer 11

Changes in cells

Question 12

How does one go about diagnosing potentially malignant lesion histopathologically?

Answer 12

Fist look at architectural changes

Then assess cytology of the tissue

Question 13

How can one GRADE epithelial dysplasia

Answer 13

HYPERPLASIA

MILD

MODERATE

SEVERE

CARCINOMA IN SITU

Question 14

What is basal hyperplasia?

Answer 14

Increased number of basal cells

Architecture
- regular stratification of layers
- basal cell layer enlarged

Cytology
- no cellular atypia

Question 15

How would the grade: mild dysplasia appear histopathologically?

Answer 15

Architecture
- changes in lower third

Cytology - mild atypia
- pleomorphism of cells
- hyperchromatism of cells
- basal cell hyperplasia

Question 16

How would the grade: moderate dysplasia present histopathologically?

Answer 16

Architecture
- middle third extension of changes

Cytology
- moderate cellular atypia

Question 17

How would the grade: severe dysplasia present histopathologically?

Answer 17

Architecture - changes extending into upper third

Cytology
- severe atypia
- numerous mitoses

Question 18

How might carcinoma in situ present histopathologically?

Answer 18

Architecture
- abnormal
- full thickness changes

Cytology
- pronounced atypia
- frequent mitosis abnormalities

Question 19

What genes are involved in oral cancer progression?

Answer 19

Oncogenes and TSG

TP53 TSG

Genes that regulate apoptosis

Genes involved in DNA repair

Viral genes??

Question 20

how can gene expression be altered?

Answer 20

TSG and oncogenes

DNA methylation

Histone modification

Gene mutation

Question 21

What are the 6 hallmarks of cancer

Answer 21

Self sufficient growth signals
Insensitivity to growth inhibition signals
Tissue invasion and metastases
Limitless replicative potential
Self sustained angiogenesis
Evading apoptosis

Question 22

How is the pattern of invasive front related to nodal spread?

Answer 22

Non-cohesive front of invasion is more linked to nodal spread

Question 23

How does oral cancer spread through the tissues?

Answer 23

1. Local invasion of disease to adjacent tissues
2. Lymphatic spread
3. Haematogenous spread

Question 24

How can oral cancer spread to bone?

Answer 24

Through gaps in the cortex of the bone in edentulous spaces

Through a dentate individual via the PDL

Question 25

How is cancer clinically STAGED?

Answer 25

Staging = TNM

Grading = low, moderate and high

Question 26

Give some subtypes of OSCC

Answer 26

Basaloid squamous

Spindle cell

Verrucous carcinoma