Red and White Lesions of the Oral Cavity

Overview

WHITE LESIONS

1. Leukoplakia

• Robbins, Cotran & Kumar Pathologic Basis of Disease, p. 684
• Fitzpatrick's Dermatology, p. 1906

• Most common potentially malignant oral lesion; global prevalence 0.5–3.4%
• Peak incidence age >40 years; male:female = 2:1
• 6× more common in smokers vs. non-smokers

Non-homogeneous leukoplakia of the lateral tongue with irregular verrucous surface — histology confirmed severe dysplasia

Oral leukoplakia: well-demarcated, non-homogeneous white plaque on the lateral border of the tongue

• Tobacco — strongest risk factor (smoked and smokeless forms); areca/betel nut
• Alcohol — synergistic with tobacco
• HPV — detected in up to 22% of lesions; high-risk subtypes (HPV 16, 18) implicated as independent risk factors
• Chronic mechanical trauma (linea alba, morsicatio) → frictional keratosis — NOTE: these resolve when the irritant is removed and are NOT true leukoplakia
• Fitzpatrick's Dermatology, p. 1907

• Simple hyperkeratosis + acanthosis (no dysplasia) → lowest risk
• Mild/moderate dysplasia → atypical mitoses, nuclear pleomorphism
• Severe dysplasia / carcinoma in situ → highest risk
• Transformation into invasive SCC occurs when dysplastic cells breach the basement membrane
• Fitzpatrick's Dermatology, p. 1907

• Clinical diagnosis of exclusion
• Eliminate causative factors (tobacco, trauma) for 2–6 weeks; if no resolution → mandatory biopsy
• Biopsy directly if no causative factor identified, or if symptomatic

• Tobacco/frictional keratosis, candidiasis (pseudomembranous — can be scraped off), lichen planus, linea alba, leukoedema, white sponge nevus, hairy leukoplakia, lupus erythematosus, verrucous/squamous cell carcinoma

• Overall rate ~2–3% per year across all subtypes
• 5–25% of leukoplakias are premalignant
• High-risk features: epithelial dysplasia, non-homogeneous clinical subtype, floor of mouth/ventral tongue location, female sex, long duration, large lesion size
• Cummings Otolaryngology, p. 1582; Robbins & Kumar, p. 684

• Eliminate risk factors (tobacco cessation, alcohol reduction)
• Surgical excision or CO₂ laser ablation (treatment of choice)
• Regular surveillance with biopsy of suspicious areas
• No consensus on medical therapy; topical retinoids have been used with limited evidence

2. Hairy Leukoplakia

• White, confluent patches with fluffy ("hairy") corrugated/shaggy surface
• Almost always bilateral lateral borders of tongue
• Cannot be scraped off (unlike candida)
• Robbins, Cotran & Kumar, p. 683

Fig. 87.8 (Cummings): Oral hairy leukoplakia along the lateral tongue margin — vertically corrugated keratotic ridges

• HIV/AIDS (may portend AIDS development)
• Post-transplant immunosuppression
• Hematologic malignancies, cancer chemotherapy

3. Oral Lichen Planus (OLP)

Classic reticular OLP: delicate white Wickham striae in net-like pattern on buccal mucosa

Erosive lichen planus: Wickham striae with focal deep-red erosive lesions on the lower lip mucosa

4. Other White Lesions

RED LESIONS

1. Erythroplakia

• Fitzpatrick's Dermatology, p. 1908
• Robbins, Cotran & Kumar, p. 684

• Rarest oral OPMD; prevalence 0.02–0.83%
• Middle-aged adults; male predominance
• Associated with reverse cigar smoking (chutta smokers of India)

• Asymptomatic, solitary, sharply demarcated erythematous macule or patch
• Surface smooth, soft, velvety (occasionally pebbled)
• Most common sites: soft palate, floor of mouth, buccal mucosa
• Usually <1.5 cm; up to 4 cm described
• Induration = highly suspicious for invasive SCC

Erythroplakia: well-demarcated, bright red, velvety patch on the lateral tongue. The thin epithelium reveals underlying vasculature — ~90% harbor dysplasia/CIS/invasive SCC

• Tobacco, alcohol, areca nut (same risk factors as leukoplakia)
• High p53 tumor suppressor gene mutation rate — explains high malignant potential
• The red color results from epithelial atrophy (thin epithelium makes underlying vasculature visible) + subepithelial vascular dilatation + inflammatory reaction

• ~90% show severe dysplasia, carcinoma in situ, or minimally invasive carcinoma — the most ominous histology of any OPMD
• Rarely demonstrates orderly epithelial maturation
• Robbins, Cotran & Kumar, p. 684

• Biopsy mandatory to rule out invasive carcinoma
• Surgical excision or CO₂ laser
• Lesions >80 mm² carry significantly higher risk of recurrence post-excision

2. Erythematous Candidiasis

• Red, atrophic patches without the white pseudomembrane
• Common on hard/soft palate (denture stomatitis) and dorsal tongue (median rhomboid glossitis)
• Often asymptomatic or burning sensation
• Responds to antifungal therapy

3. Other Red Lesions

MIXED RED AND WHITE LESIONS

Speckled Erythroplakia (Erythroleukoplakia)

• Combined red and white areas; the red foci within a mixed lesion carry the highest risk of dysplasia/malignancy
• Often represents advanced disease requiring urgent biopsy

Erosive Lichen Planus

• White striae surrounding central erythematous/erosive zones
• Bilateral buccal distribution characteristic

Pemphigus/Pemphigoid

• Pemphigus vulgaris: vesicles/bullae rupturing → hyperemic erosions with exudate; positive Nikolsky sign; IgG anti-desmoglein antibodies
• Mucous membrane pemphigoid: subepidermal blistering; gingiva most commonly affected (desquamative gingivitis)

Comparative Risk of Malignant Transformation

Key Diagnostic Principles

1. Cannot be scraped off → leukoplakia, hairy leukoplakia, lichen planus, white sponge nevus
2. Can be scraped off → pseudomembranous candidiasis
3. Bilateral, symmetric, lacy → oral lichen planus (reticular)
4. Red, velvety, ≥80% dysplasia → erythroplakia (biopsy urgently)
5. White + red mixed → speckled erythroplakia (highest-risk component = red areas)
6. Lateral tongue, HIV/immunosuppressed, corrugated → hairy leukoplakia (EBV)
7. Any white/red lesion persisting >2 weeks after removing irritant → BIOPSY

Recent Evidence

🎭 The Oral Cavity's Silent Drama: A Story of White, Red & Fibrous Villains

Imagine the oral cavity as a stage. Most days, the pink, moist mucosa performs its routine — talking, tasting, chewing. But sometimes, uninvited characters walk on stage: white ghosts, red flames, and a slow-moving concrete wall. Each one tells a story. Learn to read their lines — because some of them are whispering about cancer.

ACT I: THE WHITE CHARACTERS 🤍

🎭 Character #1 — LEUKOPLAKIA: "The White Mask"

"I cannot be wiped away. I cannot be explained. I simply exist — white, fixed, and watching."

• Buccal mucosa (its favorite hiding spot)
• Floor of the mouth and ventral tongue (danger zones)
• Palate, gingiva

• Hyperkeratosis + acanthosis → just thickened, no real trouble
• Mild → moderate dysplasia → abnormal mitoses, nuclear pleomorphism begin
• Severe dysplasia → carcinoma in situ → basement membrane breach → invasive SCC

Non-homogeneous leukoplakia — lateral tongue, irregular verrucous surface. Histology: severe dysplasia

1. Remove the irritant (tobacco, sharp tooth) — wait 2–6 weeks
2. Didn't resolve? → BIOPSY without further debate
3. Symptomatic? → BIOPSY immediately

🎭 Character #2 — HAIRY LEUKOPLAKIA: "The Shaggy Ghost"

"I haunt only the weak — those whose immune system has already surrendered."

• Bilateral lateral borders of the tongue — white, corrugated, shaggy/hairy ridges
• Cannot be scraped off (unlike thrush)
• Ranging from subtle white streaks to thick corrugated plaques

Oral hairy leukoplakia: bilaterally corrugated keratotic ridges on the lateral tongue margin

🎭 Character #3 — ORAL LICHEN PLANUS: "The Lace Artist"

"I am autoimmune. My T-cells are confused, and they have turned your mucosa into a canvas of white lace — and sometimes, burning wounds."

Reticular OLP: delicate arborescent Wickham striae on buccal mucosa — the classic asymptomatic presentation

Erosive OLP: white striae surrounding raw, red erosions — the painful, high-risk variant

🎭 Other White Supporting Characters

ACT II: THE RED CHARACTERS 🔴

🔥 Character #4 — ERYTHROPLAKIA: "The Silent Inferno"

"I am small. I am red. I am quiet. And I am almost always malignant."

• Asymptomatic, solitary, sharply demarcated red velvet patch
• Soft, velvety surface (occasionally pebbled/stippled)
• Most common sites: soft palate, floor of mouth, buccal mucosa
• Usually <1.5 cm, but deceptively quiet
• Induration = invasion has likely begun

Erythroplakia: well-demarcated bright red velvety patch on the lateral tongue — ~90% harbor severe dysplasia or carcinoma

🔴 Other Red Supporting Characters

ACT III: THE SLOW STRANGLER 🧱

🎭 Character #5 — ORAL SUBMUCOUS FIBROSIS (OSMF): "The Concrete Wall"

"I start as a burn in your mouth. Then I quietly build walls — fibrous, relentless, invisible at first. One day, you realize you cannot open your mouth wide enough to eat. That is when I introduce myself."

• Common forms: paan, gutka, pan masala, mawa, supari
• Also associated with heavily chili-seasoned diets

Stage 1: Burning sensation → erythema (the mouth's SOS signal)
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Stage 2: Mucosal pallor — the pink fades to marble-white as fibrosis builds
         ↓
Stage 3: Fibrous bands appear — palpable cord-like structures in buccal mucosa, 
         palate, tonsillar pillars, fauces
         ↓
Stage 4: Trismus — mouth opening progressively restricted
         ↓
Stage 5: Tongue fixation — speech, swallowing impaired
         ↓
Stage 6: Ulceration + leukoplakic patches appear
         ↓
Stage 7 (~7–30% of cases): Malignant transformation → ORAL SCC

OSMF: pale, marble-like buccal mucosa with prominent vertical fibrous bands — a classic premalignant picture

Advanced OSMF: restricted mouth opening (trismus) with blanched fibrotic mucosa

• Atrophic epithelium sitting directly above submucosal fibrosis — the classic "juxtaposition of atrophic epithelium to subadjacent fibrosis"
• Loss of rete ridges, homogenized collagen bundles, reduced vascularity
• Chronic inflammatory cell infiltrate in early stages

• 🚫 Stop the areca nut — the single most important step (but fibrosis already laid down does NOT reverse)
• 💉 Intralesional injections — triamcinolone or dexamethasone ± hyaluronidase (to break down collagen)
• 🌿 Antioxidant therapy — spirulina (shown to reduce fibrosis and malignant transformation risk in trials)
• 🏋️ Physiotherapy — jaw-opening exercises to maintain function
• 🔪 Surgery — fibrous band release ± skin/mucosal grafting in advanced trismus; CO₂ laser ablation
• Surveillance for malignant transformation is lifelong

THE FINAL SCORECARD: Who Is the Most Dangerous?

THE GOLDEN DIAGNOSTIC RULES 🔑

Rule 1: Any lesion that cannot be scraped off → leukoplakia, OLP, hairy leukoplakia, OSMF Rule 2: Any lesion that can be scraped off → pseudomembranous candidiasis Rule 3: Bilateral + lacy white lines → oral lichen planus (reticular) Rule 4: Red + velvety + sharply demarcated → erythroplakia — BIOPSY TODAY Rule 5: Betel nut habit + burning + pale buccal bands + trismus → OSMF Rule 6: Corrugated lateral tongue + immunosuppressed → hairy leukoplakia (EBV) Rule 7: Any white or red lesion persisting >2 weeks after removing the irritant → BIOPSY, no excuses