MJDF Oral & Dental Pathology 2

Question 1

What are the histological features of oral squamous cell carcinoma (OSCC)?

Accepted Answer

Invasive islands of malignant squamous cells with nuclear pleomorphism, abnormal mitoses, and keratin pearl formation

Answer

OSCC shows invasive nests of squamous epithelium with nuclear pleomorphism, hyperchromatism, abnormal mitoses, individual cell keratinisation, and keratin pearl formation in well-differentiated cases.

Question 2

What is the most common site for oral cancer in the UK?

Accepted Answer

Lateral border of the tongue

Answer

The lateral border and ventral surface of the tongue is the most common site for oral squamous cell carcinoma in the UK, accounting for approximately one-third of all cases.

Question 3

What is the mechanism by which tobacco causes malignant transformation in oral epithelium?

Accepted Answer

Nitrosamines and polycyclic aromatic hydrocarbons form DNA adducts, causing mutations in tumour suppressor genes (TP53)

Answer

Carcinogens in tobacco (nitrosamines, PAHs) form covalent DNA adducts, leading to mutations — particularly in TP53 tumour suppressor gene — driving malignant transformation of oral epithelium.

Question 4

What percentage of leukoplakia undergoes malignant transformation?

Accepted Answer

Approximately 1–3% (higher for homogeneous; higher in non-homogeneous/speckled types)

Answer

Overall, approximately 1–3% of leukoplakia cases undergo malignant transformation; non-homogeneous (speckled, nodular, verrucous) subtypes carry a higher risk than homogeneous leukoplakia.

Question 5

What is the significance of erythroplakia compared to leukoplakia?

Accepted Answer

Much higher malignant transformation rate (>40%) and more likely to contain dysplasia at presentation

Answer

Erythroplakia (red patch) carries a far higher rate of dysplasia or carcinoma in situ at presentation (>40–50%) than leukoplakia, making it a more serious potentially malignant disorder.

MJDF Part 1 Practice Test

MJDF Part 1 Practice Test

MJDF Oral & Dental Pathology 2