Oral Submucous Fibrosis

Presented by:Dr Kalpajyoti Bhattacharjee

CONTENTS Introduction Definition Epidemiology Nomenclature Classification Etiopathogenesis Clinical features Histopathology Differential diagnosis Special investigations Malignant potential Treatment and Management

INTRODUCTION

Oral mucous membrane is a unique area of the body, which

is continuously exposed to various kinds of stresses such as

heat, cold, microorganisms, chemicals and mechanical

irritations.

In response to these stresses, both epithelium and

connective tissue layers of the oral mucosa exhibit acute and

chronic reactive changes.

One such reaction of the collagen of oral mucosa to arecanut

is oral submucous fibrosis.

Oral Submucous Fibrosis (OSMF) is a chronic disease of

insidious onset and a prevailing potentially malignant disorder

characterized by juxta-epithelial inflammatory reaction along

with mucosal fibrosis.

OSMF is characterized by deposition of dense collagen in the

connective tissue

First described by Schwartz “atrophica idiopathic mucosae

oris” in 1952 among 5 Indian females in Kenya.

1953- Joshi from Bombay redesignated the condition as

Submucous Fibrosis.

Most widely accepted definition by Pindborg JJ & Sirsat S.M (1966)

states-

“OSMF is an insidious chronic disease affecting any part of the oral

cavity and sometimes the pharynx. Although, occasionally

preceeded by and/or associated with vesicle formation, it is always

associated with juxta epithelial inflammatory reaction, followed by a

fibroelastic change of the lamina propria, with epithelial atrophy

leading to stiffness of the oral mucosa and causing trismus and

inability to eat”.

DEFINITION

EPIDEMIOLOGYOral submucous fibrosis (OSF), first described in the early 1950s, is

a potentially malignant disease predominantly seen in people of Asian

descent.

The disease is predominantly seen in India, Bangladesh, Sri Lanka,

Pakistan, Taiwan, Southern China, Polynesia and Micronesia. Several

case-series are reported among Asian immigrants to the UK and

South and East Africa. A significant variation in the prevalence of OSF

in different countries has been reported.

Pindborg (1980) quotes it as almost exclusively occurring among

Indians, Pakistanis and Burmese.

The condition was first described in ancient Indian Manuscripts

by Sushruta describing it as “VEDARI” where he describes

patients suffering from narrowing of mouth, burning sensation

and pain.

The prevalence of this condition in Indian subcontinent is a

reflection of their food, cultural or religious habits.

More prevalent among younger individual (15-35 years)

2.3:1- M:F

NOMENCLATURE

AUTHORS YEAR NOMENCLATURE GIVENSchwartz 1952 Atrophia Idiopathica mucosa oris

Joshi 1953 Submucosa fibrosis of palate and pillars

Lal 1953 Diffuse oral submucous fibrosis

Su 1954 Idiopathic scleroderma of mouth

De sa 1957 Submucous fibrosis of palate and check

George 1958 Submucous fibrosis of palate and mucosa membrane

Pindborg& Sirsat 1964 Oral submucous fibrosis

Goleria 1970 Sub-epithelial fibrosis

CLASSIFICATION

Based on clinical findings

Pindborg JJ 1989

Stage I- Stomatitis; erythematous mucosa, vesicles,

ulcers, petechiae

Stage II- Fibrosis in healing vesicles and ulcers;

blanching, palpable bands, mottled marble like appearance

Stage III- Sequelae of OSMF; Leukoplakia, speech and

hearing deficit

Lai DR 1995

Based on interincisal distance

Group 1- >35mm

Group 2- between 30 and 35mm

Group 3- between 20 and 30mm

Group 4- <20mm

13

Haider SM (2000)

Clinical stage:

Stage I: faucial bands only

StageII: faucial and buccal bands

Stage III: Faucial, buccal and labial bands.

Functional stage:

I. Mouth opening ≥ 20 mm.

II. Mouth opening 11-19 mm.

III. Mouth opening ≤10 mm.

Prakash R. et al Based on morphologic variants of soft palate

Type 1: Leaf shaped

Type 2: Rat tail shaped

Type 3: Butt shaped

Type 4: Straight line

Type 5: Deformed S

Type 6: Crook shaped

15

• Grade I : Epithelium shows Hyperkeratosis, intra cellular

edema, little basal cell hyperplasia, rete ridges present.

Histological classification- Bailor D.N.

• Grade II : Epithelium undergoing atrophy, rete ridges less

prominent, connective tissue showing thickened collagen

bundles, less cellularity, fibrosed blood vessels with moderate

amount of hyalinization.

• Grade III : Marked atrophy of epithelium, absence of rete ridges,

connective tissue showing abundant hyalinization, cellularity

absent in connective tissue.

etioPATHOGENESIS

ETIOLOGY

Multifactorial

Local factors:

Chillies and

Arecanut

Systemic factors :

Nutritional deficiency,

Genetic predisposition and

Autoimmunity.

Epidemiological and in vitro experimental studies - chewing areca

nut is the major etiological factor.

Chillies- Capsaicin, an active principle, mild irritant, which brings about

epithelial and connective tissue changes in OSMF patients.

Elastic degradation of collagen and ultrastructurally, partial or

complete degeneration of collagen into elastin-like filaments,

sheets or dense amorphous material. (Sirsat & Khanolkar 1960).

Mutogenic and enhance the tumorigenicity of tobacco in

experimental animals. (Bhide 1992)

Increases the risk of cancers in the upper aero digestive

tract in a dose- dependent manner. (Notani 1992)

Nutritional deficiencies

May be secondary

OSMF patients cannot tolerate spicy food & the opening of

the mouth in OSF patients becomes smaller which may affect

normal food intake and lead to nutritional deficiencies.

Arecanut:

Four alkaloids- Arecoline, Arecaidine, Guvacine, Guvacoline.

Arecoline – main agent. (Tilakaratne 2006).

Flavanoid components- tannins and catechins.

Fibroblastic proliferation and inceased collagen formation.

Chronic placement of betel quid (areca nut)

Arecoline

Fibrosis

Rigidity & limited mouth opening

ROLE OF ARECOLINE

Arecoline

( Slaked lime) (Hydrolysis )

Arecaidine

Fibroblast stimulation & proliferation

Increased collagen synthesis

Large quantity of tannin present in areca nut

Inhibits collagenases

Reduced collagen degradation

Stabilization of collagen by tannins (and catachins polyphenols)

Arecoline + tannin → ↓ degradation of collagen ↑ production of collagen

Arecoline

Increased generation of ROS (oxidative stress)

Activates various transcription factors ( NF kappa B, JNK & p38 MAPK)

Stimulates CTGF (fibroblasts and endothelial cells)

Fibroblastic proliferation and increased collagen formation.

Arecoline

Increased production of Tissue inhibitors of metalloproteinase (TIMP)

Inhibits activated collagenase

Increased production of collagen/decreased degradation of collagen

Arecoline altering p53, checkpoint kinase

G2/M cell cycle arrest

Supresses endothelial cell population

Atrophy of epithelium & hypoxic environment

carcinogenesis

Arecoline + keratinocytes

differentiation Fibroblast myofibroblast

ECM contraction

fibrosis

Presence of Copper in nut:

Copper content in areca nut

( Increased activity of lysyl oxidase enzyme )

Fibroblast stimulation & proliferation

Increased collagen synthesis

MATRIX METALLOPROTEINASES AND TISSUE INHIBITORS OF MATRIX METALLOPROTEINASES

Arecoline

Increased ROS and DNA double strand breaks produced by damaged mitochondria

TIMP-1 & 2/ MMP-1

Collagen production / collagen degradation

fibrosis

Fibrogenic cytokines

External stimuli

Increased levels of cytokines in the lamina propria

Induce development of disease

TGF-ß Platelet derived growth factor (PDGF)

Basic fibroblast growth factor (bFGF)

ACCUMULATION OF COLLAGEN AND OTHER CHANGES IN ECM

Early stage – tenascin, fibronectin, perlecan and collagen type III

were enhanced in lamina propria and submucosa.

Intermediate stage – elastin extensively and irregularly deposited

around muscle fibres together with above mentioned molecules

Advanced stage – all the ECM molecules get decreased and

replaced by collagen type I

Heat shock protein (HSP 47) is a collagen specific molecular

chaperone involved in the processing and/or secretion of

procollagen. HSP 47 is significantly upregulated in OSF. Arecoline

was found to elevate HSP 47 expression in fibroblasts.

Cystatin C, a non glycosylated basic protein is increased in a

variety of fibrotic diseases, Cystatin C was found to be

upregulated both at m–RNA and protein levels in the disease.

Arecoline is responsible for this enhancement in a dose

dependent manner

EPITHELIAL MESENCHYMAL TRANSITION (EMT)

ANE caused cell injury

ROS

MAPK & NF kB pathways involved in EMT

Alteration of normal keratinocyte

morphology

Keratinocytes PGE2, IL-6, TNFα and TGFβ

fibrosis

GROWTH FACTORS AND INFLAMMATORY CYTOKINES

ANGIOGENESIS RELATED MOLECULES

Overexpression of iNOS, b-FGF, TGF-β, PDGF, HIF-1α

(increased MVD)

Maintain vascularity of underlying CT

Adaptive response of mucosa to cope up with the hypoxia caused by fibrosis

HYPOXIA

Extensive fibrosis

Reduction in vascularity

Hypoxia

atrophy & ulceration overexpression of HIF-1α

malignant transformation

ALTERATIONS OF CELL CYCLE

PCNA index is higher in OSF epithelium than normal oral

mucosa – increased malignant transformation potential.

Important molecules in G2/M phase ( cyclin B1, p34 and p-

survivin) are over expressed malignant transformation by

inhibition of apoptosis and encouraging mitosis in carcinogenesis.

Survivin as both prognostic and predictive marker in malignant transformation of OSF

GENETIC SUSCEPTIBILITY

Genomic instability (LOH)

Absence of tumor suppressor genes

Malignant transformation of OSF

CLINICAL FEATURES

EARLY OSMF ADVANCED OSMF

Burning sensation

Blisters

Ulcerations

Excessive salivation

Defective gustatory sensation

Dryness of mouth

Blanced

Slightly opaque

White fibrous bands (vertically)

Fixation, shortening or deviation of uvula

Impairment of tongue movement

Inability to blow or whistle

Difficulty in swelling

Nasal voice

Blanching seen over left buccal mucosa

Blanching seen on ventral surface of tongue, floor of mouth and restricted movements of tongue

Decreased mouth opening in oral submucous fibrosis patient

Soft palate and faucial pillars showing redness

Soft palate showing blanching and shrunken uvula seen inthe posterior part

Histopathology

Histological findings in OSMF cases were found to vary depending on

the clinical severity of the cases and the site of biopsy

The observed epithelial changes are secondary to changes in

connective tissue.

The findings range from normal to atrophic and hyperplastic epithelium

(Sirsat & Khanolkar, 1957).

Pindborg and Sirsat (1966) observed marked changes in the form of

atrophy of epithelium with loss of rete pegs in 90% of the cases as

compared to normal oral mucosa.

EPITHELIAL CHANGES

The atrophic epithelium also exhibits intracellular edema, signet

cells and epithelial atypia (focal dysplasia).

Epithelial keratinization, especially the tendency of atrophic and

hyperplastic epithelium to show keratinization was higher when

compared to normal.

Increased mitotic activities were evident in a small number of

cases

Classical oral submucous fibrosis (OSMF) showing thin atrophic epithelium with chronic inflammation and dense fibrosis in the submucosa (hematoxylin-eosin, original magnification 200).

CONNECTIVE TISSUE CHANGES

Pindborg et al (1966) have described four consecutive stages in

submucous fibrosis cases based on sections stained with

haemotoxylin and eosin:

The changes are based on following criteria

Presence or absence of edema

Nature of the collagen bundles

Overall fibroblastic response

State of the blood vessels

Predominant cell type in the inflammatory exudates

Very early stage

Fine fibrillar collagen dispersed with marked edema and

strong fibroblastic response showing plump young fibroblasts

containing abundant cytoplasm will be observed.

Blood vessels - occasionally normal, but more often they are

dilated and congested.

Inflammatory cells- polymorphonuclear leukocytes with

occasional eosinophils, are present.

Early stage

In this stage juxta-epithelial area shows early hyalinization.

The collagen is still seen as separate bundles which are

thickened.

Plump young fibroblasts are present in moderate numbers.

The blood vessels are often dilated and congested.

The inflammatory cells are mostly lymphocytes, eosinophils

and the occasional plasma cells.

Histopathological picture showing early changes in the oral submucous fibrosis

Moderately advanced stage

In this stage, the collagen is moderately hyalinised.

The amorphous change starts from the juxta-epithelial basement

membrane.

Occasionally, thickened collagen bundles are still seen separated

by slight residual edema.

The adult fibroblastic cells have elongated spindle shaped nuclei

and scanty cytoplasm.

Blood vessels are either normal or constricted as a result of

increased surrounding tissue.

The inflammatory exudate consists of lymphocytes, plasma cells

and occasional eosinophils.

Advanced stage

The collagen is completely hyalinised and is seen as a

smooth sheet with no distinct bundles or edema

Hyalinised connective tissue becomes hypocellular with thin

elongated cells.

Blood vessels are completely obliterated or narrowed.

The inflammatory exudate consists of lymphocytes and

plasma cells and occasional eosinophils.

Interestingly the melanin containing cells in the lamina propria

are surrounded by dense collagen, which explains the

clinically observed loss of pigmentation.

Histopathological picture of advanced stage oral submucous fibrosis showing atrophied epithelium, increased fibrosis and hyalinization of submucosal tissues

Khanna and Andrade (1995); grouped OSMF features into 4 groups based on histopathological features:

Group I : Very early changes Common symptom is burning sensation in the mouth. Acute ulceration and recurrent stomatitis Not associated with mouth opening limitation.Histology: Fine fibrillar collagen network interspersed with marked edema. Blood vessels dilated and congested. Large aggregate of plump, young fibroblasts present with

abundant cytoplasm. Inflammatory cells mainly consist of polymorphonuclear

leukocytes with few eosinophils. Epithelium normal.

Group II : Early cases Buccal mucosa appears mottled and marble-like Widespread sheets of fibrosis palpable Patients with an interincisal distance of 26-35mm

Histology: Juxtaepithelial hyalinization present Collagen present as thickened but separate bundles. Blood vessels dilated and congested Young fibroblasts seen in moderate number Inflammatory cells mainly consist of polymorphonuclear

leukocytes with few eosinophils and occasional plasma cells. Flattening or shortening of epithelial rete pegs evident with

varying degree of keratinization.

Group III : Moderately advanced cases Trismus evident with an interincisal distance of 15-25mm Buccal mucosa appears pale and firmly attached to underlying

tissues Atrophy of vermilion border Vertical fibrous bands palpable at the soft palate,

pterygomandibular raphe and anterior faucial pillars.

Histology: Juxtaepithelial hyalinization present Thickened collagen bundles faintly discernible, separate by very

slight, residual edema. Blood vessels, mostly constricted Mature fibroblasts with scanty cytoplasm and spindleshaped nuclei

Inflammatory exudates consists mainly of lymphocytes Epithelium markedly atrophic with loss of rete pegs Muscle fibers seen interspersed with thickened and dense

collagen fibers.

Group IV A : Advanced cases: Trismus is severe with interincisal distance of less than 15mm The fauces are thickened, shortened and firm on palpation. Uvula is shrunken and appears as a small, fibrous bud Tongue movements are limited On palpation of lips, circular band felt around entire mouth.Group IV B: Advanced cases with premalignant and malignant changes. Hyperkeratosis, leukoplakia, or squamous cell carcinoma can

be seen.

Histology: Collagen hyalinized as smooth sheet. Extensive fibrosis obliterating the mucosal blood vessels and

eliminating the melanocytes. Fibroblasts markedly absent within the hyalinized zones. Total loss of epithelial rete pegs. Mild to moderate atypia present. Extensive degeneration of muscle fibers evident

(a) Loss of striation in muscle; (b) Floculant material showing degeneration

OSMF showing extensive fibrosis in the submucosa (hematoxylin-eosin, original magnification 200).

OSMF with lichenoid reaction, showing bandlike inflammatory exudate with fibrosis (hematoxylin-eosin).

SPECIAL INVESTIGATIONS

SPECIAL STAINS

Van Gieson's Stain

Masson's trichrome stain

Picrosirius red

IHC MARKERSHeat shock proteins 47

Cystatin c

Survivin

Endothelial markers- CD31,

CD34, CD105

Basic fibroblastic growth factor

P53

Bcl-2

Ki-67

DIFFERENTIAL DIAGNOSIS

Scleroderma Fibroma Generalized fibromatosis Anemia Amyloidosis

MALIGNANT POTENTIAL

The precancerous nature of OSF was first discovered by Paymaster (1956), when he observed slow growing squamous cell carcinoma in one third of the patients with the disease.

This was confirmed with various groups & Pindborg (1972) put forward five criteria to prove that the disease is precancerous. They included:

1. High occurrence of OSF in oral cancer patients2. Higher incidence of squamous cell carcinoma in patients with

OSF3. Histological diagnosis of cancer without any clinical suspicion

in OSF4. High frequency of epithelial dysplasia &5. Higher prevalence of leukoplakia among OSF.

Malignant transformation rate of OSF was found to be in the range of 7–13% (Tilakaratne 2006).

According to long-term follow-up studies a transformation rate of 7.6% over a period of 17 years was reported (Murti1985).

BIOLOGICAL STUDIES

Blood chemistry and haematological variations.

Iron, vitamin B12, folate levels

ESR, anemia and eosinophilia, gammaglobulin

TREATMENT

1) Restriction of habits: Reduction or elimination of habit of areca nut chewing is an

important preventive measure.

2) Corticosteroids: suppresses inflammatory response by their anti-inflammatory

action. It prevents fibrosis by decreasing fibroblastic proliferation and

deposition of collagen. local injection (intralesional injection), topical applications or

in the form of mouth washes.

3) Hyaluronidase: Break down hyaluronic acid, lower the viscosity of the

intercellular cement substance and also decreases collagen formation.

Intralesional injection of Hyalase used in the dose of 1500 IU, Chymotrypsin 5000 IU, Fibrinolytic agents (Hyalase) dissolved in 2% lignocaine.

4) Placental Extracts: The combination of dexamethasone, hyaluronidase and placental

extract were found to give better results than with a single drug

5) Nutritional support: High proteins, calories, vitamin B complex, other vitamins and minerals.

6) Physiotherapy: forceful mouth openings, heat therapy.

7) Surgical treatment: cutting the fibrotic bands resulted in more fibrosis and disability.

Excision of fibrotic tissues and covering the defect with split thickness skin, fresh human amnion or buccal fat pad (BFP) grafts have been applied to treat OSMF

8) Stem cell therapy Recently scientists have proven that intralesional injection

of autologous bone marrow stem cells is a safe and effective treatment modality in oral sub mucosal fibrosis.

Autologous bone marrow stem cell injections induces angiogenesis in the area of lesion which in turn decreases the extent of fibrosis thereby leading to significant increase in mouth opening

Possible therapeutic interventions for OSF

CONCLUSION

In summary, the available literature indicates that the main

aetiological factors for OSF are the constituents of areca nut,

mainly arecoline, whilst tannin may have a synergistic role.

The use of Areca nut should be avoided in commercial

smokeless tobacco products. It is an urgent need to educate

people about the adverse effects regarding oral cavity.

Future research should also focus on targeting various

molecules and pathways which have been identified, in order

to search for effective treatment as morbidity and mortality is

significantly higher in OSF.

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