STEPTRACKERGASTROINTESTINAL | PATHOLOGY | HIGH-YIELD REVIEW

Oral Cavity & Salivary Glands

White and red patches, oral cancers, and salivary gland tumors — most parotid tumors are benign.

FOCUS ON
White lesions: thrush scrapes off; leukoplakia doesn't and needs a biopsy; hairy leukoplakia is EBV in HIV and not premalignant. Oral SCC comes from tobacco and alcohol; oropharyngeal SCC from HPV-16 (p16⁺, better prognosis). Parotid tumors: pleomorphic adenoma (most common), Warthin, mucoepidermoid carcinoma (most common malignant).
LESION
CAUSE
FEATURES
CLUE
Aphthous ulcers
Idiopathic, stress; associated with Behçet, Crohn, celiac
Painful, shallow ulcers with gray base and red rim
Recurrent canker sores
Oral candidiasis (thrush)
Candida albicans; HIV, inhaled steroids, antibiotics, infants, diabetes
White plaques that scrape off, leaving a red base
Esophageal spread in AIDS
Oral hairy leukoplakia
EBV in immunosuppression (HIV)
White, corrugated plaques on the lateral tongue; won't scrape off
Not premalignant
Leukoplakia · erythroplakia
Tobacco, alcohol, chronic irritation
White (leukoplakia) or red velvety (erythroplakia) plaque that can't be scraped off
Precancerous — biopsy; erythroplakia has higher dysplasia risk
Oral squamous cell carcinoma
Tobacco (smoked, chewed, betel quid), alcohol; UV for lip
Floor of mouth, lateral tongue, lower lip; spreads to cervical nodes
Non-healing ulcer in a smoker-drinker
HPV-related oropharyngeal SCC
HPV-16 (E6/E7) — younger, often non-smokers
Tonsils, base of tongue; early neck node
p16 ⁺; better prognosis than tobacco-related SCC
Pleomorphic adenoma
most common salivary tumor
Benign mixed tumor
Painless mobile parotid mass; epithelium + chondromyxoid stroma; finger-like projections
Recurs if enucleated; can turn malignant (facial palsy = warning)
Warthin tumor
Benign; smoking
Parotid; cysts lined by double layer of oncocytes over lymphoid stroma with germinal centers
Older male smokers; bilateral or multifocal
Mucoepidermoid carcinoma
most common malignant
Malignant salivary tumor
Parotid; mucinous + squamous cells
Pain, facial nerve involvement
Sialadenitis
Mumps; S aureus (dehydrated, postoperative); stone (sialolithiasis)
Painful gland swelling; ↑ amylase in mumps
Mumps: bilateral parotitis, orchitis, pancreatitis

Mechanism — two routes to oral SCC

Tobacco + alcoholSynergistic
→
Leuko-/erythroplakia
→
Dysplasia
→
Oral SCCp53 mutation
HPV-16Tonsillar crypts
→
E6 → p53, E7 → Rbp16 rises
→
Oropharyngeal SCCBetter prognosis

Salivary gland tumors

TUMOR
BEHAVIOR
HISTOLOGY
CLUE
Pleomorphic adenoma
Benign
Epithelium + chondromyxoid stroma
Recurs if incompletely removed
Warthin
Benign
Oncocytes + lymphoid stroma
Smokers; bilateral
Mucoepidermoid
Malignant
Mucous + squamous cells
Facial nerve
Adenoid cystic
Malignant
Cribriform pattern
Perineural spread; minor glands

The smaller the gland, the more likely a tumor is malignant: parotid tumors are mostly benign, minor-gland tumors often malignant.

How it's tested

COMMON CONFUSIONHairy leukoplakia (EBV, HIV, not premalignant) is not leukoplakia (tobacco, premalignant). Both are white and can't be scraped off.
THE TRAPA parotid mass with new facial nerve weakness is malignant until proven otherwise. Benign tumors push nerves aside; cancers invade them.
YOUR APPROACHWhite or red? Scrapes off? Patient risk (HIV, smoking, HPV)? For a salivary mass: which gland, nerve involvement, histology.

If you see… think…

Painless mobile parotid mass in a middle-aged woman → pleomorphic adenoma
Parotid tumor that recurred after enucleation → pleomorphic adenoma
Parotid mass + new facial palsy → malignant tumor
Older male smoker, bilateral cystic parotid masses → Warthin tumor
HIV patient with corrugated white lateral tongue plaques → hairy leukoplakia (EBV)
White plaques that wipe off leaving a raw base → candidiasis
White plaque in a smoker that doesn't scrape off → leukoplakia — biopsy
Red velvety patch on the floor of the mouth → erythroplakia (high risk)
Young non-smoker with tonsillar mass, p16⁺ → HPV-16 oropharyngeal SCC
Bilateral parotitis + orchitis → mumps