L.16 white lesions and oral keratoses

White Lesions(Oral Keratosis)

Dr. Hind Ahmed Osman

• Normal color of oral mucosa depends on:

1)Vascularity.

2)Epithelial thickness

3)Keratinization

4)Melanin pigmentation

2 Dr. Hind Ahmed Osman

Causes of white lesions:Causes of white lesions:1.1. Hyperkeratosis:Hyperkeratosis: thickening of keratin layer. thickening of keratin layer.

2.2. Acanthosis:Acanthosis: epithelial hyperplasia due to epithelial hyperplasia due to increase in spinous cell layer.increase in spinous cell layer.

3.3. Spongiosis:Spongiosis: Intracellular epithelial edema. Intracellular epithelial edema.

4.4. Reduced vascularityReduced vascularity of underline connective of underline connective tissue.tissue.

5.5. Submucosal deposits:Submucosal deposits: tumors or anomalies. tumors or anomalies.

6.6. Surface debrisSurface debris or fibrinous exudate. or fibrinous exudate.

7.7. Fungal coloniesFungal colonies..


• White patches may be due to increased or White patches may be due to increased or abnormal production of keratin which appears abnormal production of keratin which appears white in the wet oral environment: white in the wet oral environment: they cannot they cannot be scraped off.be scraped off.

• Accumulation of debris and desquamated cells Accumulation of debris and desquamated cells on oral mucosa may also result in white areas: on oral mucosa may also result in white areas: can be scraped off.can be scraped off.

Dr. Hind Ahmed Osman4

• Classification:

1) Clinical classification: It depends on whether the white lesion can be wiped away or not.


• Classification:

2) Histological classification: It depends on presence of epithelial dysplasia.


Classification: Classification: 1.1. Developmental conditions.Developmental conditions.

2.2. Hereditary diseases.Hereditary diseases.

3.3. Reactive lesions.Reactive lesions.

4.4. Infective lesions.Infective lesions.

5.5. Immunologically-mediated conditions.Immunologically-mediated conditions.

6.6. Premalignant lesions & conditions.Premalignant lesions & conditions.

7.7. Non-epithelial white-yellow lesions.Non-epithelial white-yellow lesions.

8.8. Neoplastic lesionsNeoplastic lesions


1.1. Developmental conditions:Developmental conditions:• Fordyce’s granules.Fordyce’s granules.

• Ectopic lymphoid tissue.Ectopic lymphoid tissue.


2. Hereditary conditions2. Hereditary conditions..• Leukoedema.Leukoedema.

• White sponge nevus.White sponge nevus.

• Hereditary benign intraepithelial dyskeratosis.Hereditary benign intraepithelial dyskeratosis.

• Follicular keratosis (Darrier’s disease).Follicular keratosis (Darrier’s disease).


3. Reactive lesions.3. Reactive lesions.• Mechanical: frictional keratosis, lip and cheek Mechanical: frictional keratosis, lip and cheek

biting.biting.

• Physical: thermal burns, electric burns, Physical: thermal burns, electric burns, radiation mucositis.radiation mucositis.

• Nicotinic stomatitis.Nicotinic stomatitis.

• Hairy tongue.Hairy tongue.

• Tooth paste-associated slough.Tooth paste-associated slough.

• Chemical: mucosal aspirin burnChemical: mucosal aspirin burn


4. Infective lesions4. Infective lesions• Candidiasis.Candidiasis.

• Syphilitic leukoplakia.Syphilitic leukoplakia.

• Hairy leukoplakia.Hairy leukoplakia.


5. Immunologically-mediated conditions.5. Immunologically-mediated conditions.

• Lichen planus.Lichen planus.

• Lupus erythematosus.Lupus erythematosus.

• Geographical tongue.Geographical tongue.


6. Premalignant lesions & conditions:6. Premalignant lesions & conditions:A) Classification of precancerous lesionsA) Classification of precancerous lesions::

• Actinic cheilitis (UV light, lower lip).Actinic cheilitis (UV light, lower lip).

• Idiopathic leukoplakia (unknown).Idiopathic leukoplakia (unknown).

• Palatal keratosis associated with reversed Palatal keratosis associated with reversed smoking.smoking.

• Smokeless tobacco keratosis (snuff).Smokeless tobacco keratosis (snuff).

• Erythroplakia (unknown).Erythroplakia (unknown).


B) Classification of precancerous conditions:B) Classification of precancerous conditions:• Oral submucous fibrosis.Oral submucous fibrosis.• Lichen planus .Lichen planus .• Lupus erythematosus.Lupus erythematosus.• Candidiasis.Candidiasis.• Plummer-Vinson syndrome. Plummer-Vinson syndrome. • Syphilitic leukoplakia.Syphilitic leukoplakia.• Xeroderma pigmentosum.Xeroderma pigmentosum.• Pachyonychia congenita.Pachyonychia congenita.• Dyskeratosis congenita.Dyskeratosis congenita.• Epidermolysis bullosa. Epidermolysis bullosa. 14 Dr. Hind Ahmed Osman

7. Non-epithelial white-yellow lesions.7. Non-epithelial white-yellow lesions.• Gingival cysts of infancy.Gingival cysts of infancy.• Parulis.Parulis.• Lipoma.Lipoma.


8. Neoplastic lesions8. Neoplastic lesions• Squamous cell carcinoma.Squamous cell carcinoma.

• Verrucous carcinomaVerrucous carcinoma..


. Hereditary conditions (Genodermatosis). Hereditary conditions (Genodermatosis)• Leukoedema.Leukoedema.

• White sponge nevus.White sponge nevus.

• Hereditary benign intraepithelial dyskeratosis.Hereditary benign intraepithelial dyskeratosis.

• Follicular keratosis (Darrier’s disease).Follicular keratosis (Darrier’s disease).


LeukoedemaLeukoedema

• Leukoedema is usually discovered as an incidental finding. Leukoedema is usually discovered as an incidental finding. • It is asymptomatic and symmetrically distributed in the buccal It is asymptomatic and symmetrically distributed in the buccal

mucosamucosa• It appears as a gray-white, diffuse, filmy, or milky surface It appears as a gray-white, diffuse, filmy, or milky surface

alterationalteration• Presents as a translucent, milky whiteness of the surface of the Presents as a translucent, milky whiteness of the surface of the

mucosa with a slightly folded appearance.mucosa with a slightly folded appearance.• It tends to disappear on stretching.It tends to disappear on stretching.

Histology:Histology:• Acanthosis with broadened rete ridges.Acanthosis with broadened rete ridges.• Superficial prickle cells appear vacuolated and contain Superficial prickle cells appear vacuolated and contain

glycogen.glycogen.


Oral Epithelial Nevus (White Sponge Nevus)Oral Epithelial Nevus (White Sponge Nevus)

• Autosomal dominant. The mutations in genes coding for Autosomal dominant. The mutations in genes coding for keratins 4 & 13.keratins 4 & 13.

• Benign conditionBenign condition• Edges not well-defined.Edges not well-defined.• It affects oral mucosa bilaterally and symmetricallyIt affects oral mucosa bilaterally and symmetrically Lesions tend to be thickened and have a spongy consistencyLesions tend to be thickened and have a spongy consistencyfolded appearance.folded appearance.• Age; Children.Age; Children.

Histopathology:Histopathology: Acanthosis.Acanthosis. Hyperparakeratosis.Hyperparakeratosis. Intracellular edema of prickle and parakeratinized cell layers.Intracellular edema of prickle and parakeratinized cell layers.


Hereditary benign intraepithelial dyskeratosisHereditary benign intraepithelial dyskeratosis

• An autosomal dominant genodermatosisAn autosomal dominant genodermatosis

• Childhood.Childhood.

• Oral and conjuctival mucosa.Oral and conjuctival mucosa.

• Oral mucosa: resemble leukoedma or white Oral mucosa: resemble leukoedma or white sponge nevus.sponge nevus.

• Ocular lesions: thick opaque gelatinous Ocular lesions: thick opaque gelatinous plaques on bulbar conjunctiva.plaques on bulbar conjunctiva.


Follicular keratosis (Darier’s disease)Follicular keratosis (Darier’s disease)

• It is an autosomal dominant genodermatosis.It is an autosomal dominant genodermatosis.

• Etiology: lack of cohesion among surface Etiology: lack of cohesion among surface epithelia cells.epithelia cells.

• Skin lesions: pruritic papules with Skin lesions: pruritic papules with accumulation of keratin producing accumulation of keratin producing foul odorfoul odor..

• painful splitting of nails.painful splitting of nails.

• Oral lesions: multiple white flat-toped papules Oral lesions: multiple white flat-toped papules in hard palate & alveolar mucosa. in hard palate & alveolar mucosa.



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L.16 white lesions and oral keratoses