Dental Pathology Lecture Notes: Red, White, Purple, and Pigmented Lesions

Reactive, Traumatic, and Inflammatory Red and Purple Lesions

• General Characteristics

  • Usually caused by constant forces, trauma, or tissue laceration.
  • Most instances are mild but result in chronic inflammation and an exuberance of tissue.
  • Surface is typically smooth.
  • The primary response to injury in these cases is excess tissue accompanied by chronic inflammation.

• Pyogenic Granuloma

  • Definition: Benign vascular growths representing an exuberant response (hyperplastic granulation) of tissue to trauma or irritation.
  • Alternative Names: Pregnancy tumor, pregnancy granuloma, epulis gravidarum, and puberty granuloma.
  • Transmission: This condition is neither contagious nor infectious.
  • Etiologies: Can be triggered by drugs, hormones, foreign irritants, and systemic involvement.
  • Frequency and Location: Found in both oral and extraoral locations; however, $75\%$ of the time it occurs on the gingiva.
  • Demographics: Puberty and pregnancy are peak times for occurrence due to significant increases in hormone levels. Changes in hormones may cause the lesion when irritating particles like calculus are present.
  • Characteristics:
    • Younger lesions appear bright red.
    • Older lesions transition to more pink or darker shades/hues.
    • Base can be pedunculated (on a stalk) or sessile (broad base).
    • Note: Despite the name "pyogenic," it is NOT a pus-forming lesion or abscess.
  • Treatment (Tx):
    • During pregnancy, lesions are often observed and not immediately removed.
    • Lasers are frequently used for removal.
    • Surgical removal is a standard option.
    • Scaling and the use of rinses such as Chlorhexidine are common.
    • Clinicians should promote good home care; women should maintain dental appointments before and during pregnancy to maintain a healthy mouth.

• Peripheral Giant Cell Granuloma (PGCG)

  • Definition: Localized reactive hyperplastic responses to tissue injury.
  • Demographics: Typically affects an older age group, mostly between the $40s$ and $50s$. There is a slight prevalence in females.
  • Frequency: This is the least frequently seen of the reactive-type lesions of the gingiva.
  • Location: Occurs on oral tissue, typically the gingiva or edentulous ridges.
  • Size: Generally measures $1\text{--}2\,cm$.
  • Clinical Appearance: Deep red or bluish color; characterized as being "less red" than a pyogenic granuloma. Texture ranges from soft to somewhat firm.
  • Radiographic/Clinical Effect: Bone resorption is possible.
  • Histology: Contains giant cells, fibroblasts, and more fibrous connective tissue (CT). It is less vascular than other reactive lesions, which explains why it is less colorful.
  • Treatment (Tx):
    • Complete excision is required.
    • Removal must specifically involve the periosteum and the ligament.
    • Surgery and lasers may be used in combination.
    • The underlying irritant must be removed.
  • Home Care: Scaling and root planing, frequent maintenance appointments, and follow-up oral exams.

• Hemorrhagic Lesions (Petechia, Purpura, and Ecchymoses)

  • General Rule: All three types (Petechia, Purpura, and Ecchymoses) WILL NOT blanch with diascopy.
  • Petechia:
    • The smallest category; pinpoint size measuring $1\text{--}2\,mm$.
    • Mostly caused by trauma from objects like sharp chips, rough foods, ill-fitting dentures, or dental appliances.
    • They are not vascular in nature.
    • Systemic Implication: Frequent petechiae may indicate blood disorders such as Leukemia.
  • Purpura:
    • The middle-sized category; larger than $2\,mm$.
    • Can be caused by trauma or systemic disease.
    • Systemic Implication: May indicate leukemia; other clinical signs might include frequent nosebleeds and bruising.
  • Ecchymoses:
    • The largest of the three hemorrhages; greater than $2\,mm$.
    • Traumatic Causes: Biting oral tissues, objects like fingers or spoons, or toothbrush use in eating disorders such as Bulimia.
    • Iatrogenic Causes: Dental drills, patient biting down unexpectedly, or poor rubber dam placement.
    • Other Causes: Fellatio (oral sex) may also be a consideration.

• Hematoma

  • Definition: An area of blood pooled under the skin, often called a "blood blister."
  • Clinical Testing: Diascopy would reveal no disruption of blood supply.

Immune System Disorders

• Lichen Planus

  • Definition: A chronic disorder of unknown etiology.
  • Location: Can occur on oral, genital, esophageal, anal, and skin areas.
  • Epidemiology: Affects $0.5\%\text{--}5\%$ of the population worldwide. Women are most often affected. Typically occurs in midlife (ages $30\text{--}80$).
  • Specific Forms of Lichen Planus:
    • Reticular Form: Classic lace-like pattern.
    • Papular Form.
    • Plaque Form.
    • Atrophic Form (Erythematous Form): Red patches that may occur with other forms; also known as desquamative gingivitis.
    • Bullous Form: Consists of vesicles ranging from a few millimeters to larger sizes.
    • Erosive Form: Ulcerative with stripping of the epithelium. This is the most aggressive form, is painful, and is more difficult to treat. It has a higher notation for transforming into Squamous Cell Carcinoma (SCC).
  • The Four P’s of Cutaneous (Skin) Lichen Planus:
    • Purple: Color (Note: This color is ONLY on skin, NOT intraorally).
    • Pruritic: Itchy.
    • Polygonal: Specific shape.
    • Plaques: Slightly raised/crusted lesions.
  • Lichenoid Reactions: These are reactions to a specific product rather than the systemic disease. Common triggers include amalgam, toothpaste, flavoring agents, or drugs. These often occur unilaterally where the tissue contacts the offending product.
  • Treatment (Tx):
    • Topical corticosteroids.
    • Discontinuation of offending products.
    • Plaque reduction and frequent maintenance visits.
    • Documentation of lesions and oral cancer screenings with biopsies if tissue changes occur.
    • Possible transformation of erosive lesions to SCC (small percentage of patients).

• Hypersensitivity Reactions

  • Classification: Type IV/delayed and cell-mediated reactions.
  • Common Triggers: Foods (flavoring), environment, dental products (toothpaste, mouthrinse), and dental materials (amalgam or crown materials).

Infections of the Oral Cavity

• Candidosis (Candidiasis)

  • General: Most common fungal infection, often called "Thrush."
  • Erythematous Candida: Lesions appear red and raw when wiped off.
  • Appearance: Plaque-like or cottage cheese-like in some forms.
  • Locations: Typically found in the pharynx, tongue, buccal mucosa, and mucosal folds.
  • Chronic Erythematous Type: Bright red; very common in denture wearers.
  • Symptoms: Burning sensation or altered taste.
  • Risk Factors: Immunocompromised status, xerostomia, elderly, and infants (pseudomembranous form).

• Angular Cheilitis (Perleche)

  • Location: Occurs at the commissure (corners) of the mouth.
  • Etiology: As corners of the mouth droop (common in older individuals due to loss of muscle structure), saliva collects, allowing Candida to thrive. This is especially common in patients with Diabetes.
  • Appearance: Area may crack, peel, appear ulcerated, or crusted.
  • Treatment (Tx): Antifungals such as Nystatin (topical ointment).

• Median Rhomboid Glossitis

  • Definition: Rhombus-shaped area of central denuded papillae (papillary atrophy) on the tongue.
  • Etiology: Linked to C. albicans; once thought to be developmental, it is now believed to be an acquired fungal condition. Sometimes a "kissing lesion" appears on the palate where it contacts the tongue.
  • Risk Factors: Smokers and denture wearers.
  • Treatment (Tx): Antifungals.

Neoplasms and Vascular Malformations

• General Oncology

  • Benign tumors: Do not spread but can cause pain and pressure on nerves as they expand.
  • Malignant tumors: May spread throughout the body.

• Erythroplakia (Erythroplasia)

  • Definition: A velvety red patch that cannot be diagnosed as any other condition.
  • Risk Factors: Increased alcohol and tobacco use; nutrition and lifestyle also play roles.
  • Speckled Leukoplakia: Also known as erythroleukoplakia; a lesion containing both red and white components.
  • Clinical Significance: Any red lesion should be biopsied and considered precancerous. At least $85\%$ are usually severely dysplastic. It has a high rate of progressing to oral cancer.
  • Typical Sites: Floor of the mouth, soft palate, and buccal mucosa.

• Varicosity/Varix

  • Definition: Abnormally dilated or tortuous veins.
  • Venous Varix: Found on the lower lip, typically in adults over $60\,years$ old. Rare in children. Appears as a dark blue spot. The vessel wall weakens from chronic sun exposure. Melanoma should be ruled out for cosmetic/clinical safety.
  • Lingual Varicosities: Found under the tongue, usually in older adults. Diascopy confirms blood supply. The primary concern is thrombosis (blood clot).

• Congenital Hemangioma

  • Definition: Benign proliferation of blood vessels composed of capillaries and venules.
  • Diagnosis: They blanch with pressure (diascopy), which differentiates them from a hematoma.
  • Management: Usually no treatment is needed as most involute (resolve) on their own.
  • Location: Most common on the central tongue.

• Lymphangiomas

  • Etiology: Occur during embryogenesis and are present at birth.
  • Location: Tongue (most common), buccal mucosa, floor of mouth.
  • Composition: Lymphatic vessels containing RBCs within channels and lymph tissue.
  • Appearance: Colors range from clear to dark blue and red.
  • Note: These lesions DO NOT involute. They may exhibit a "thrill" (pulsing) and may require surgical removal.

• Hereditary Hemorrhagic Telangiectasia (HHT)

  • Alternative Name: Osler-Weber-Rendu Disease.
  • Genetics: Autosomal dominant inheritance.
  • Timeline: Evident at birth and increases with age.
  • Clinical Features: Dilated blood vessels ("spider veins") on lips and tongue. Papules will blanch. May bleed profusely or appear as an ulcer.
  • Systemic Concerns: Frequent nosebleeds, strokes, and brain abscesses.
  • Related Conditions: Patients with CREST syndrome (scleroderma) usually exhibit telangiectasias.

White Lesions: Variations of Normal and Traumatic

• General Terms

  • Hyperkeratosis: Thickening of the horny layer of the epidermis/mucosa caused by increased keratin production.
  • Leukoplakia: An undiagnosed white patch that does not rub off; considered a premalignant state if other specific diagnoses are ruled out.

• Fordyce Granules

  • Definition: Normal, ectopic sebaceous glands.
  • Epidemiology: Evident in $80\%$ of the population. Equally affects males and females. Not seen in children; appears starting at puberty/adolescence.
  • Location: Lower lip and buccal mucosa, often bilaterally symmetrical.
  • Characteristics: Asymptomatic (painless); may present as a few or hundreds of granules.

• Leukoedema

  • Demographics: Equal sex predilection; more common in African Americans.
  • Identifying Marker: Does NOT rub off, but it disappears when the tissue is stretched.

• Geographic Tongue (Inflammatory)

  • Epidemiology: Affects $2\%\text{--}3\%$ of the population. Rare in children; female predilection.
  • Appearance: Atrophic, denuded patches on the dorsal and ventral tongue. Red portions represent depapillation of filiform papillae. There are yellow or white concentric rings (the border of inflammation).
  • Treatment (Tx): Generally none as it resolves on its own. If burning or altered taste occurs, mouth rinses or steroids may be used.

• Traumatic White Lesions

  • Frictional Keratosis: Whitish plaques caused by physical irritation (adaptive callus). Not considered leukoplakia.
  • Linea Alba: Localized friction occurring along the occlusal line on the buccal mucosa. May indicate bruxism.
  • Cheek Chewing (Morsicatio Buccarum/Labiorum): Over-production of keratin due to chronic trauma (behavioral habit). Can be confused with white sponge nevus.

• Nicotine Stomatitis

  • Etiology: Heavy smoking or reverse smoking involving chemical and heat irritation.
  • Appearance: White keratinized tissue where minor salivary gland duct openings appear as red dots.

• Hairy Tongue

  • Definition: Elongation of the filiform papillae on the dorsal tongue.
  • Causes: Antibiotics, radiation therapy, smoking, peroxide use, or overgrowth of flora.
  • Appearance: Hair-like projections (white or brown). Fissuring may appear but is not true fissuring.
  • Treatment (Tx): Tongue cleaner, toothbrush debridement, and sometimes Chlorhexidine gluconate.

• Chemical and Thermal Burns

  • Caustic Agents: Aspirin (placed on tooth for pain), phenols, silver nitrate, hydrogen peroxide.
  • Pathology: Necrosis of the epithelium (Coagulation Necrosis) where cells lose their nuclei, resulting in a white color.

White Lesions: Infections and Immune Disorders

• Pseudomembranous Candidiasis

  • Key Feature: DOES rub off.
  • Risk Factors: Broad-spectrum antibiotics, corticosteroid use, smoking, xerostomia, diabetes.

• Chronic Hyperplastic Candidiasis

  • Key Feature: WILL NOT wipe off.
  • Significance: Only form of Candida with malignant potential ($15\%$ may become dysplasia). Indistinguishable from leukoplakia clinicaly.
  • Treatment (Tx): Oral/topical antifungals, Vitamin A/retinoids, laser, or surgical intervention.

• Hairy Leukoplakia

  • Etiology: Infected with EBV (Epstein-Barr Virus); often seen in those who had Mononucleosis.
  • Demographics: Secondary to immunosuppression (HIV/AIDS or organ transplant patients).
  • Note: Does not rub off.

• Parulis

  • Definition: Gingival swelling due to drainage of a sinus tract from a periodontal or pulpal infection.
  • Appearance: Purulent exudate (yellow pus) indicating an odontogenic infection.

• Lichen Planus (White Forms)

  • Mechanism: T-lymphocytes recruited to skin/mucosa; chronic cell-mediated response (not classified as a true autoimmune disease as no antigen has been found).
  • Visual Marker: Wickham striae (lattice-work pattern).
  • Forms: Reticular and plaque forms appear as white lesions.
  • Koebner Phenomenon: Affects sites prone to trauma.
  • Histology: Hyperkeratotic with "saw-tooth" angular rete ridges and liquefaction of the basal cell layer.

• White Sponge Nevus

  • Genetics: Rare, inherited autosomal dominant condition; mutation of keratin genes.
  • Appearance: Widespread keratinization of buccal mucosa; flows down into the vestibule (helps differentiate it from cheek chewing).

Premalignant and Malignant White/Pigmented Lesions

• Proliferative Verrucous Leukoplakia (PVL)

  • Characteristics: Aggressive, progressive form with a high incidence of oral cancer. Appears as a raised cauliflower-like or pebbly lesion, often on the gingiva.

• Oral Submucous Fibrosis (OSF)

  • Causes: Areca nut chewing (Betel Quid), genetic predisposition.
  • Mechanism: Arecoline (chemical in nuts) causes fibroblasts to over-produce collagen. Strong bands inhibit oral opening, tongue movement, and speech.
  • Visuals: Dark staining on tissues; considered premalignant.

• Oral Melanoma

  • Demographics: Most often males in the $50\,year$ age group.
  • Location: Found mostly on the hard palate and maxillary gingiva.
  • Prognosis: Poor; spreads laterally through tissue.

Raised Lesions with a Rough or Papillary Surface

• Oral Squamous Papilloma (Oral Wart)

  • Etiology: Capable of transmitting HPV. Affects $7\%\text{--}10\%$ of the population.
  • Note: HPV can spread by autoinoculation.

• Verruca Vulgaris (Common Wart)

  • Strains: HPV $1$, $2$, $4$, $26$, $27$, $40$, and $41$ (all low risk).
  • Transmission: Usually autoinoculation from fingers to mouth.

• Condyloma Acuminatum (Venereal Warts)

  • Strains: HPV $6, 11, 16, 18$. Specifically $16$ and $18$ are high-risk strains for which many are vaccinated.
  • Transmission: Direct oral-oral or oral-genital contact.

• Focal Epithelial Hyperplasia (Heck Disease)

  • Strains: HPV $13$ and $32$ (low risk).
  • Appearance: Pink to whitish, translucent, cauliflower-like surface. Most often in younger age groups.

• Verrucous Carcinoma (Snuff Dippers' Cancer)

  • Etiology: Highly related to spit tobacco (snuff/chew); alcohol increases risk.
  • Contagion: Not thought to be contagious.

Pigmented Lesions Essentials

• Lead-Line Stain (Burtonian Line): Blue, gray, or black line in the premolar gingival region indicative of lead poisoning (Plumbism) in children.
• Minocycline Stain: Semi-synthetic tetracycline used for acne; causes black bone staining and dark staining of hard/soft tissues.
• AZT (Zidovudine): Drug used for AIDS that may cause nail and tongue pigmentation.
• Amalgam Tattoo (Focal Argyrosis): Amalgam fragments forced into tissue during restorative work; confirmed via radiograph.