FIBROMA (Oral Cavity)

Oral Pathology - BDS 3rd Year University Exam Notes

1. DEFINITION

2. SYNONYMS

• Irritation fibroma
• Traumatic fibroma
• Focal fibrous hyperplasia
• Bite fibroma
• Fibrous nodule / Fibrous hyperplasia

3. ETIOLOGY AND PATHOGENESIS

• Repeated cheek/lip biting (most common)
• Ill-fitting dentures or prostheses
• Sharp edges of broken teeth or restorations
• Calculus or foreign bodies
• Chronic friction from orthodontic appliances

4. INCIDENCE AND EPIDEMIOLOGY

5. CLINICAL FEATURES

• Most commonly on the buccal mucosa along the bite line (occlusal line)
• Also occurs on: lower labial mucosa, anterolateral tongue, gingiva
• Less commonly: palate, floor of mouth

• Sessile or pedunculated, firm nodule
• Smooth, pink surface - similar in colour to surrounding normal mucosa
• Usually asymptomatic unless repeatedly traumatized
• Surface may be:
  • Normal pink (most common)
  • White/keratotic (due to friction)
  • Ulcerated (due to biting or acute trauma)

• Usually < 1.5 cm in diameter
• Rarely exceeds 1.5 cm

6. HISTOPATHOLOGICAL FEATURES

• Unencapsulated mass (not encapsulated - important exam point)
• Hyperplastic fibrous connective tissue in the submucosa
• Dense, minimally cellular fascicles of collagen fibres
• Relatively avascular appearance (hypovascular stroma)
• Minimal inflammatory infiltrate (sparse)
• Overlying epithelium may be:
  • Normal
  • Atrophic (thinned)
  • Hyperkeratotic (thickened white surface)
  • Ulcerated (secondary to continued biting)
• Fibroblasts are mature and bland (no nuclear atypia or mitoses)

Key histology exam point: Dense collagen bundles, few fibroblasts, minimal vascularity, unencapsulated - overlying epithelium may be normal, atrophic, or hyperkeratotic.

7. VARIANTS / TYPES OF ORAL FIBROMAS

8. RADIOGRAPHIC FEATURES

• Irritation fibroma is a soft tissue lesion - does NOT show any radiographic changes in underlying bone
• No bony erosion or expansion
• X-ray is not routinely required unless bony involvement is suspected

9. DIFFERENTIAL DIAGNOSIS

10. TREATMENT

• Conservative surgical excision is the treatment of choice
• Excision should include the base of the lesion down to the submucosal layer
• The precipitating cause must be eliminated (e.g., smoothing sharp teeth, refitting dentures, stopping cheek-biting habits)
• Histopathological examination of the excised specimen is mandatory to confirm the clinical diagnosis and rule out malignancy
• Recurrence is unlikely if the causative trauma is removed
• If irritation persists, recurrence may occur

11. PROGNOSIS

• Excellent prognosis
• No malignant potential
• Low recurrence rate when cause is addressed
• (Compare: Peripheral ossifying fibroma has 15-20% recurrence)

12. CLASSIFICATION - WHERE FIBROMA FITS

• Connective Tissue Hyperplasia (normal-appearing overlying mucosa):
  • Irritation fibroma ← this lesion
  • Denture-associated hyperplasia (fibrous epulis)
  • Palatal papillomatosis
  • Drug-induced gingival hyperplasia (phenytoin, nifedipine, cyclosporine)
  • Hereditary gingival fibromatosis

13. QUICK REVISION BOX (Exam Essentials)

14. IMPORTANT EXAM QUESTIONS FIBROMA COMMONLY APPEARS IN

1. "Write a short note on irritation fibroma."
2. "Describe the clinical and histopathological features of fibroma."
3. "Enumerate the reactive lesions of the oral cavity and describe fibroma."
4. "Differentiate between fibroma and pyogenic granuloma."
5. "Write the differential diagnosis of a soft tissue swelling on buccal mucosa."

• Robbins, Cotran & Kumar - Pathologic Basis of Disease - Fibrous Proliferative Lesions, Chapter 16
• Cummings Otolaryngology Head & Neck Surgery - Oral Cavity: Fibroma, p. 1644
• Dermatology 2-Volume Set 5e - Oral Fibroma section
• Goldman-Cecil Medicine - Table 393-5: Oral Soft Tissue Tumors

FIBROMA

As Per Shafer's Textbook of Oral Pathology, 10th Edition

Chapter 6: Non-Epithelial (Connective Tissue) Tumours of the Oral Cavity

1. DEFINITION

2. SYNONYMS (Shafer's Classification)

• Irritation fibroma
• Traumatic fibroma
• Focal fibrous hyperplasia
• Fibrous nodule
• Hyperplastic scar
• Inflammatory fibrous hyperplasia

3. CLASSIFICATION OF FIBROMAS IN SHAFER'S

4. IRRITATION FIBROMA (FOCAL FIBROUS HYPERPLASIA)

A. Etiology and Pathogenesis

• Reactive lesion caused by chronic, repetitive trauma to oral mucosa
• Represents overexuberant fibrous connective tissue repair resulting in a submucosal fibrous mass
• Common causes:
  • Chronic cheek/lip biting (most common - occlusal trauma)
  • Ill-fitting dentures or dental prostheses
  • Sharp tooth cusps or broken restorations
  • Calculus deposits
  • Orthodontic appliances
• NOT a true fibroblastic neoplasm; this is a key Shafer's emphasis

B. Clinical Features

1. Buccal mucosa along the bite line (occlusal line) - most common
2. Lower labial mucosa
3. Lateral border of tongue
4. Gingiva
5. Palate (less common)

• Smooth-surfaced, sessile (broad-based) or pedunculated nodule
• Firm in consistency
• Pink or pale pink - similar to or slightly paler than surrounding mucosa (due to relative avascularity)
• Surface can be:
  • Normal and smooth (most common)
  • Hyperkeratotic/white - due to chronic friction
  • Ulcerated - due to acute biting trauma
• Usually painless (asymptomatic), unless traumatized

Shafer's key point: Multiple oral fibromas may be associated with Cowden syndrome (multiple hamartoma syndrome).

C. Histopathological Features (High Yield)

• Unencapsulated submucosal nodular mass (no capsule - important!)
• Dense collagen bundles in a haphazard or fascicular arrangement
• Collagen may be hyalinized in older lesions
• Fibroblasts are mature, widely scattered, and bland (no atypia, no mitoses)
• Relatively avascular (few blood vessels - hence pale color clinically)
• Sparse chronic inflammatory cells, usually in a perivascular distribution
• Overlying stratified squamous epithelium may show:
  • Normal appearance
  • Atrophy (thinning)
  • Hyperkeratosis (thickening - due to chronic friction)
  • Ulceration (with secondary acute inflammatory infiltrate)

Exam mnemonic: "Dense Collagen, Few Fibroblasts, Avascular, Unencapsulated" = DCFAU

5. GIANT CELL FIBROMA

Clinical Features

• Relatively uncommon variant
• More common in young adults (1st-3rd decade; younger than irritation fibroma)
• Common sites: gingiva, tongue, and palate
• Presents as a small, papillary or pebbly-surfaced nodule (unlike the smooth surface of irritation fibroma)
• Usually < 1 cm; asymptomatic

Histopathological Features (Distinctive)

• Contains numerous large, stellate-shaped (star-shaped) and multinucleated fibroblasts - this is the hallmark
• These large cells are concentrated in the superficial (subepithelial) connective tissue
• Central areas contain typical fusiform fibroblasts
• Overlying epithelium often corrugated/papillary with thin, elongated rete ridges (unlike irritation fibroma where rete ridges are broad or absent)
• Relatively less collagen than irritation fibroma

Developmental analogue: The retrocuspid papilla is a developmental lesion histologically similar to giant cell fibroma; it occurs almost exclusively on the lingual gingiva of mandibular canines in children and young adults.

6. PERIPHERAL OSSIFYING FIBROMA

Clinical Features

• Exclusively on the gingiva (not on other oral mucosa)
• Highest incidence in young females (female predilection more marked)
• Appears as a red, ulcerated, nodular gingival swelling
• May arise from a pre-existing pyogenic granuloma that has matured, or de novo from cells of the periodontal ligament (PDL)
• Most common in the maxillary anterior gingiva

Histopathological Features

• Cellular fibroblastic stroma
• Contains calcified material - a key feature:
  • Trabeculae of woven bone/osteoid
  • Droplets of basophilic cementum-like material (cementoid/cementicles)
  • Dystrophic calcification
• Overlying epithelium often ulcerated
• Highly collagenous and relatively avascular (similar to irritation fibroma)
• May contain a mild to moderate chronic inflammatory infiltrate

Treatment

• Excision must include the periodontal ligament
• Recurrence rate: 15-20% (highest among the fibromas)

7. EPULIS FISSURATUM (DENTURE-INDUCED FIBROUS HYPERPLASIA / INFLAMMATORY FIBROUS HYPERPLASIA)

Clinical Features

• Caused by chronic trauma from the flange of an ill-fitting denture
• Occurs in the alveolar vestibule (most common site)
• Appears as single or multiple elongated folds of hyperplastic tissue in the vestibule
• Tissue folds surround and grip the denture flange
• Firm, fibrous consistency; surface may be smooth or ulcerated

Histopathological Features

• Dense fibrous connective tissue with variable chronic inflammatory cells
• Surface epithelium may show hyperkeratosis or ulceration

Treatment

• Denture must be removed/refitted first
• Surgical excision of the fibrous folds

8. LEAF FIBROMA

• Occurs on the hard palate beneath a maxillary denture
• Also called denture fibroma or palatine papilloma
• Appears as a flattened pink mass attached by a thin stalk (peduncle)
• Related to suction effect of the denture

9. RADIOGRAPHIC FEATURES

• Irritation fibroma is a pure soft tissue lesion - no bony changes
• No radiographic changes seen in the underlying bone
• X-ray is not required routinely
• Exception: Peripheral ossifying fibroma may occasionally show faint calcifications on periapical X-ray in advanced cases

10. DIFFERENTIAL DIAGNOSIS

11. TREATMENT

• Surgical excision is definitive treatment
• Histopathological examination of the excised specimen is mandatory
• Remove the cause of irritation to prevent recurrence
• Recurrence is rare for irritation fibroma if cause is eliminated
• Peripheral ossifying fibroma: 15-20% recurrence rate (must excise down to periosteum)

12. PROGNOSIS

• All fibromas: excellent prognosis
• No malignant transformation potential
• Recurrence only if the causative trauma continues (irritation fibroma) or if excision is incomplete (peripheral ossifying fibroma)

13. IMPORTANT MCQ / VIVA POINTS FROM SHAFER'S

Note to student: Shafer's Textbook of Oral Pathology 10th Edition (B. Sivapathasundharam, Elsevier 2024) covers fibromas under the chapter on Non-Epithelial Neoplasms and Reactive Lesions of the Oral Cavity. The 10th edition retains the core content of previous editions on this topic while updating molecular and classification aspects. The Shafer's approach emphasizes the reactive (non-neoplastic) nature of fibroma, the importance of histopathological confirmation, and the role of eliminating the causative irritant.