Benign Epithelial and Mesodermal Lesions of the Oral Cavity

Benign Epithelial Lesions

Squamous Cell Papilloma

Age: Mid-age
Site: Palate, uvula, cheek, lip, tongue, gingiva
Characteristics:

• Color: White to pinkish (depending on keratinization)
• Shape: Cauliflower-like
• Surface: Rough, irregular (finger-like projections)
• Texture: Firm or soft (depending on keratinization)
• Sessile or pedunculated

Histological Features:

1. Hyperplastic stratified squamous epithelium
2. Acanthosis and hyperkeratosis
3. Intact basal layer
4. Thin central branching core of connective tissue carrying nutrition

Verruca Vulgaris (Wart)

Reactive lesion, autoinoculation
Etiology: HPV 2, 4, 6
Histological Features:

1. Intranuclear inclusion bodies
2. Koilocytes
3. Cupping effect of rete ridges
4. Granular cell layer

Keratoacanthoma

True, self-limiting lesion
Age: Older males
Site: Sun-exposed areas
Characteristics:

1. Color: Pink
2. Shape: Dome-shaped nodule
3. Painless, itchy
4. Texture: Firm
5. Course of Lesion:
   
   • Begins very small
   • Grows to full size (1-1.5 cm) in 4-8 weeks
   • Static for 4-8 weeks
   • Regresses, dropping core, forming a scar in 6-8 weeks

Histological Features:

1. Hyperplastic stratified squamous epithelium
2. Acanthosis and hyperparakeratosis (keratin plug)
3. Pseudoepitheliomatous hyperplasia
4. Chronic inflammation
5. No granular layer

Benign Mesodermal Lesions

Fibroma

Fibroepithelial Polyp (Irritational Fibroma)

Reactive lesion
Etiology: Chronic irritation (sharp edge, carious teeth, broken filling clasp)
Site: Gingiva, buccal mucosa
Color: Pink
Texture: Soft or firm (depending on the amount of cells and fibers)
Histological Features:

1. Hyperplastic connective tissue and epithelium
2. Acanthosis and hyperkeratosis
3. Chronic inflammatory cells (lymphocytes, plasma cells)
4. Irregular pattern, sessile or fanwise pedunculated

Denture Fissuratum (Epulis Fissuratum)

Reactive lesion
Site: Gingiva, mucolabial and mucobuccal folds
Etiology: Denture flange irritation
Appearance: Multiple ridges
Histological Features:

1. Hyperplastic epithelium (acanthosis and hyperkeratosis)
2. Hyperplastic connective tissue
3. Chronic inflammatory cells
4. Possible squamous cell carcinoma

Inflammatory Papillary Hyperplasia (Palatal Papillomatosis)

Reactive lesion
Site: Hard palate
Etiology:

1. Ill-fitting denture
2. Poor dental hygiene
3. Wearing denture 24/7

Color: Erythematous
Surface: Papillary projections, multiple small nodules
Histological Features:

1. Hyperplastic epithelium (acanthosis, hyperkeratosis)
2. Hyperplastic connective tissue
3. Chronic inflammatory cells (plasma cells, lymphocytes)
4. Nodules/crypts harboring Candida
5. Pseudoepitheliomatous hyperplasia

Peripheral Ossifying Fibroma

Reactive lesion
Gender: More common in females
Age: Young adults
Site: Exclusively on the gingiva
Characteristics:

• Color: Pink to red
• Shape: Nodular mass (pedunculated or sessile)
• Surface: Often ulcerated

Histological Features:

1. Hyperplastic epithelium and connective tissue
2. Acanthosis and hyperkeratosis
3. Chronic inflammatory cells
4. Mineralized materials