Potentially Malignant Disorders & Oral Cancer

Oral potentially malignant disorders (WHO 2020 list, main entries)

Disorder	Key point
Leukoplakia	Most common OPMD; higher risk if nonhomogeneous (speckled or nodular), on the floor of mouth or ventral/lateral tongue, or in nonsmokers
Proliferative verrucous leukoplakia	Multifocal, slowly spreading white lesions, often older women without tobacco use; very high transformation rate over time
Erythroplakia	Uncommon but most likely to show high-grade dysplasia or carcinoma at biopsy
Oral submucous fibrosis	Areca (betel) nut chewing; stiff, blanched mucosa and limited opening
Oral lichen planus and oral lichenoid lesions	Low risk, but follow-up is advised
Actinic keratosis (actinic cheilitis)	Sun-damaged lower lip vermilion; blurred vermilion border
Others	Palatal lesions in reverse smokers, discoid lupus erythematosus, dyskeratosis congenita, oral graft-versus-host disease

Dysplasia is graded by the thickness involved: mild (lower third), moderate (middle third), severe (more than two-thirds); full thickness without invasion = carcinoma in situ.

Topic	Key points
Share	More than 90% of oral cancers
Risk factors	Tobacco and alcohol (synergistic), areca nut, UV light (lip), immunosuppression; HPV-16 drives most oropharyngeal (tonsil, base of tongue) cancers
Common oral sites	Lateral and ventral tongue, floor of mouth; lower lip vermilion for lip cancer
Warning signs	Non-healing ulcer, induration, fixation, red or speckled change, unexplained loose teeth, numbness, firm fixed neck node
Spread	Ipsilateral submandibular and deep cervical (jugulodigastric) nodes; distant spread to lungs
Staging	TNM (AJCC 8th edition adds depth of invasion and extranodal extension); HPV-positive oropharyngeal cancer is staged separately and has a better prognosis
Verrucous carcinoma	Low-grade, white warty mass with pushing borders; rarely metastasizes

Do a visual and tactile head and neck exam at every new-patient and recall visit.
Remove an obvious cause and re-check in about 2 weeks; any lesion that persists, or any red, indurated or ulcerated lesion, needs biopsy or referral.
Adjunctive light or rinse tests do not replace biopsy; incisional biopsy should sample the most suspicious (red, indurated) area.
Before head and neck radiotherapy: remove hopeless teeth early (commonly about 2 weeks before), start prescription fluoride, and plan lifelong osteoradionecrosis precautions.

Treating 'leukoplakia' as a histologic diagnosis: it is a clinical term; the biopsy decides.
Assuming a nonsmoker's white lesion is low risk: PVL and nonsmoker leukoplakia can be high risk.
Using a brush or light test instead of a biopsy for a suspicious lesion.
Expecting HPV-related cancers mainly in the anterior oral cavity: they favor the oropharynx.

Pick an answer to see right away whether it is correct and why.

Which site of leukoplakia carries a higher risk of malignant change?
Epithelial dysplasia that involves the full thickness of the epithelium without invading the connective tissue is:
Most oropharyngeal squamous cell carcinomas related to HPV involve:
A 70-year-old nonsmoking woman has multiple slowly spreading warty white lesions on the gingiva and buccal mucosa over years. Concern?
Areca (betel) nut chewing with progressive limitation of opening suggests:

0 of 5 answered

Answer key: 1 B · 2 C · 3 A · 4 A · 5 D

Dental School Map · Original study material, written and checked by our team; always confirm clinical decisions against current guidelines.