Oral Cancer & Premalignancy MCQ

The highest-stakes job in oral pathology is catching squamous cell carcinoma early and recognizing the premalignant (potentially malignant) lesions that precede it. The skill is simple to state and life-saving to apply: a white patch that cannot be wiped off is leukoplakia, a red velvety patch is erythroplakia, and a sore that does not heal in about two weeks is biopsied, not watched. Tobacco, alcohol, sun (for the lip), HPV (for the oropharynx), and betel or areca nut are the drivers, and early-stage disease is far more survivable than late.

Premalignant (Potentially Malignant) Lesions

• Leukoplakia is a clinical term for a white patch that cannot be wiped off and cannot be given another specific diagnosis; it is premalignant and must be biopsied to assess for dysplasia.
• Erythroplakia is a red, velvety patch that carries a higher risk of harboring dysplasia or carcinoma than leukoplakia, so a red patch is in some ways more concerning than a white one.
• Proliferative verrucous leukoplakia is a multifocal, persistent, high-transformation variant (often in older women), and oral submucous fibrosis (from betel or areca nut) is a premalignant condition causing stiffness and limited opening.
• Epithelial dysplasia is the histologic precursor of cancer, graded mild, moderate, or severe; actinic cheilitis is the sun-induced premalignant change of the lower lip that precedes lip carcinoma.

Oral Squamous Cell Carcinoma

• Squamous cell carcinoma is by far the most common oral malignancy (about 90% of oral cancers), arising from the surface epithelium.
• The highest-risk intraoral sites are the floor of the mouth and the ventral and lateral surfaces of the tongue, followed by the soft palate complex; the lower lip is the classic site for sun-related lip cancer.
• Worrying clinical features are a non-healing ulcer, induration (a firm feel on palpation), rolled or raised borders, fixation to underlying tissue, and an exophytic or destructive mass.
• Spread is first to the cervical lymph nodes, so a hard, fixed, non-tender neck node can be the presenting sign; the definitive diagnosis of any suspicious lesion is biopsy.

Risk Factors and Field Cancerization

• Tobacco (smoked and smokeless) is the leading risk factor, and alcohol acts synergistically, so a heavy smoker who also drinks has a far higher risk than either alone.
• High-risk HPV types 16 and 18 cause a rising share of oropharyngeal squamous cell carcinoma (tonsil and base of tongue), often in younger patients without heavy tobacco or alcohol use; the HPV vaccine helps prevent these.
• Betel and areca nut use causes oral submucous fibrosis and carcinoma, and chronic sun exposure causes lip and skin cancer of the lower lip vermilion.
• Field cancerization means the entire exposed mucosa has been altered by the carcinogens, so patients are at risk for multiple and second primary cancers and need lifelong surveillance even after one lesion is treated.

Diagnosis, Other Malignancies, and Prevention

• Biopsy (histopathology) is the definitive diagnosis; adjuncts like toluidine blue staining or brush cytology can help select or flag lesions but never replace a scalpel biopsy of a suspicious area.
• Verrucous carcinoma is a low-grade, exophytic (warty) variant linked to smokeless tobacco that rarely metastasizes and carries a better prognosis; basal cell carcinoma is the most common skin cancer (sun-exposed face) and rarely metastasizes.
• Prognosis depends heavily on stage at diagnosis: early, localized oral cancer has far better survival than disease that has spread to nodes or beyond, which is exactly why early detection matters.
• Prevention is concrete: tobacco cessation, moderating alcohol, HPV vaccination, lip sun protection, and a thorough oral cancer screening examination at recall visits.