Mucosal diseases Flashcards
Describe linea alba/ traumatic keratosis in terms of:
- Pathogenesis
- Histopathology
Pathogenesis:
• Oral keratoses appear white because the thickened or abnormal keratin becomes hydrated as a result of being bathed by saliva, and then evenly reflects light
• Chronic frictional irritation leads to epithelial thickening and hyperkeratinization
• Appears on the buccal mucosa
Histopathology:
• Hyperkeratosis
• Acanthosis but there is no dysplasia
Describe fordyce granules in terms of:
- Histopathology
- Clinical signs
Histopathology:
• Consist of a number of lobules of sebaceous cells grouped around one or more ducts
Clinical:
• Sebaceous glands in the oral mucosa
• Seen as separate small, yellowish bodies beneath the surface,
• Commonly seen in the mucosa of the upper lip, cheeks, and anterior pillar of the fauces
Describe benign migratory glossitis aka geographic glossitis in terms of:
- Pathogenesis
- Clinical signs (5)
Pathogenesis:
• Inflammatory condition
• The cause of geographic tongue is unknown but geographic tongue occurs more often in patients who have psoriasis
• Not a static condition; there are periods of remission
Clinical:
• Irregular, partially depapillated, red areas on the anterior two-thirds of the tongue surface
• The margins of the lesions are often outlined by a thin, white line or band
• Associated with loss of the filiform papillae
• The fungiform papillae remaining as shiny, dark-red eminences
• Frequently associated with fissured tongue
Describe benign migratory glossitis aka geographic glossitis in terms of:
- Histopathology
Histopathology:
• Parakeratosis
• Epithelium at the edges of the lesions are acanthotic
• Dense, neutrophil leukocyte infiltration
• Munro’s microabscess:
• Vascular ectasia
Describe recurrent aphthous ulceration in terms of:
- Pathogenesis
- Histopathology
Pathogenesis:
• Idiopathic ulcers, which recur frequently
• The aetiology of RAS is unclear, but there is increasing evidence that damaging immune responses are involved
Histopathology:
• The surface of the ulcer is covered by a fibrinous exudate infiltrated by polymorphs
• Lymphocyte infiltrate by basal cells
• Beneath is a layer of granulation tissue with dilated capillaries and oedema
Describe recurrent aphthous ulceration in terms of:
- Clinical signs of minor aphthous ulcers
○ Prodromal symptoms
○ One to five, shallow, round or oval ulcers which affect the non- keratinized areas of the oral mucosa
○ Have a grey/yellow base with an erythematous margin
○ Heal without scarring
○ Common anteriorly
Describe recurrent aphthous ulceration in terms of:
- Clinical signs of major aphthous ulcers
○ Major aphthous ulcers are large greater than 1 cm in diameter
○ They may occur anywhere in the mouth, including the keratinized oral mucosa, especially posteriorly
○ Extend deep and may present as crater-like ulcers with rolled margins which are indurated on palpation because of underlying fibrosis
Describe recurrent aphthous ulceration in terms of:
- Clinical signs of herpetiform aphthous ulcers
○ Multiple, small, pin-head sized ulcers (about 1–2 mm)
○ Can occur on any part of the oral mucosa
○ As many as a hundred ulcers may be present
Describe fibroepithelial polyps in terms of:
- Histopathology
- Fibrous connective tissue
- Core of dense, relatively avascular and acellular fibrous tissue
- The surface of a fibroepithelial polyp is covered by stratified squamous epithelium which may vary in thickness and show areas of hyperkeratosis
- Typically, there is little or no inflammatory cell infiltration
Describe fibroepithelial polyps in terms of:
- Clinical signs
- Arises mainly in the cheeks, particularly along the occlusal line, lips, and tongue,
- Firm, pink, painless pedunculated or sessile polypoid swelling
- A few millimeters to centimeters in size
- Larger lesions often attach to skin by slender stalks
- Ulceration is not a feature unless the patient has bitten into the polyp.
Describe lichen planus in terms of:
- Pathogenesis
- Lichen planus is aT cell-mediated autoimmune disorder in which inflammatory cells attack an unknownproteinwithin the skin and mucosalkeratinocytes.
- Affects stratified squamous epithelium
- Present in different forms
Describe lichen planus in terms of:
- Histopathology
- Lymphocyte infiltrate beneath, killing epithelial cells (particularly, basal cells)
- If basal cells die, thickness of epithelium is reduced (atrophy), thus erythema
- Epithelium is indistinct from connective tissue
Describe lichen planus in terms of:
- Oral signs (3)
- Systemic signs (4)
Oral:
• White reticular/ network pattern of striae, bilateral, presents on checks
• Red, swollen tissues
• Open sores
Systemic: • Purplish lesions/ bumps on skin • May be itchy • Blisters • Thin, white lines over rash
Describe squamous cell papilloma:
- Pathogenesis
- Histopathology
- Clinical
Pathogenesis:
• Small benign (non-cancerous) growth that begins insquamous cells
• 50% associated with human papillomavirus
Histopathology:
• Proliferatingsquamousepithelia shown as finger like projections
• May be hyperkeratosis
Clinical:
• White-pink cauliflower-like surface projections
Describe oral submucous fibrosis in terms of:
- Pathogenesis
- Premalignant condition because it is often associated with epithelial atrophy and dysplasia
- Characterized by inflammation and progressivefibrosisof thesubmucosaltissues
Describe oral submucous fibrosis in terms of:
- Histopathology
- Hyalinization (necrosis) of the subepithelial connective tissue
- Very few fibroblasts present
- Blood vessels narrowed or totally obliterated by the fibrosis
- Lymphocytes and plasma cells are scattered throughout the hyalinized tissue
- No rete ridges
Describe oral submucous fibrosis in terms of:
- Clincal signs
- Blanched, marble appearance, often with palpable bands of fibrous tissue
- Increased stiffening of the oral mucosa associated with progressive underlying fibrosis
- Difficulty in opening the mouth and to a binding down of the tongue
Describe capillary haemangioma in terms of:
- Pathogenesis
- “Birth mark”. Non cancerous growths of numerous small capillaries which are close to the skin
- Oral lesions occur most commonly in the lips, tongue, cheeks, or palate
- May regress
Describe capillary haemangioma in terms of:
- Histopathology
- Lobules separated by thin septa containing clusters of thin walled capillaries
- Capillaries lined by a single layer of epithelium
Describe capillary haemangioma in terms of:
- Clinical signs (5)
- Bright red in colour
- Soft consistency
- Smooth, flat or raised, sometimes globular lesion of the mucosa
- Blanch on pressure
- Some may have a nodular consistency on palpation
Describe cavernous haemangioma in terms of:
- What it is
- Clinical signs
What it is:
• Made up of larger blood vessels that are dilated
• The blood vessels are not as closely packed as in a capillary haemangioma, and the spaces (or “caverns”) between them are filled with blood
Clinical signs:
• Same as capillary, except they are dark in colour
Describe cavernous haemangioma in terms of:
- Histopathological signs
- Large spaces containing blood
- Spaces lined by single layer of endothelium
Define and describe neoplasia
- Neoplasms are a new and abnormal growth of tissue in a part of the body, especially as a characteristic of cancer. It continues to grow even after the cessation of the stimuli that evoked the change
- Can be malignant or benign
- Malignant lesions metastasise
- Pathologically, benign lesions can be clinically malignant and cause death (might be compressing a vital structure or releasing hormones)
Differentiate hyperplasia from neoplasia
- Hyperplasia is the growth of tissue by increase in the size of the cells
- It can be reversible response to injury, stops upon removal of stimulus
- All cells grow, not just single clones
- Example: Fibrous epulis
- Example: Hypertrophy of muscles with exercise
State the three stages of a neoplastic growth
Initiation
Expanding clonal growth
Promotion and progression
Describe the process of initiation
- Damage to DNA by; radiation, chemicals, copy errors
- Causes uncontrolled “autonomous” growth
- “Immortal” behaviour - cells are able to keep growing in culture indefinitely but normal cells die after a defined number of divisions
- With every cell division, the ends of the chromosomes (telomeres) get shorter each time. As it gets shorter, the chromosomes cut into the DNA, and this defines the set amount of divisions a healthy cell can go through
- In neoplastic cells, a mechanism is turned on that extends the telomeres, enabling continuous division
Describe the process of expanding clonal growth
- Neoplasms arise from a single cell bearing genetic lesions
- A “cell line” grows out from this single genetically damaged cell to form the tumour
- Within this “cell line” , new genetic errors accumulate so that new sub-clonal lines emerge with development of the neoplasm
Describe the process of promotion and progression
- The proliferation of clones of cells due to external factors (like hormones)
- Cells with genetic injuries will begin to clone as well
- This increases the chances of accumulating more genetic injuries
Describe leukoplakia and state where it is most commonly found
- White patch or plaque that cannot be characterized clinically or histopathology as any other disease
- Cause is unknown
- Associated with SCC
Area of occurrence: • Floor of the mouth • Ventrolateral tongue • Soft palate • Lip
Describe the histopathology of leukoplakia
- Hyperkeratosis
- Hyperplasia (thickening of the spinous layer)
- Epithelial thickness (acanthosis/atrophy)
- Inflammatory cell infiltration in the underlying lamina propria
Describe the general signs of leukoplakia
- Small and circumscribed plaque
- Can be extensive lesion involving a large area of mucosa
- Lesions may be white, whitish-yellow, or grey and may have a homogeneous or non-homogeneous surface
Describe the features of homogenous and non- homogenous leukoplakia
Homogenous
• Plaque- like
• Smooth or wrinkled, uniform surface
Non- homogenous
• Irregular nodular/thickened surface
• Areas of redness, producing a speckled appearance, ulceration, nodular thickening, or heaping-up of the surface
Describe erythroplakia and state its clinical features
Description:
• Bright-red velvety plaque on the oral mucosa which cannot be categorized clinically or pathologically as being due to any other condition
• A lesion that shows a mixture of red and white areas is generally called speckled leukoplakia rather than erythroplakia
Clinical features:
• May be homogeneous with a well-defined but irregular outline, or may be intermingled with patches of leukoplakia
• Soft palate, ventral tongue and floor of mouth is most common areas
Describe erythroplakia in terms of its histological features
- May represent carcinomain situ
- Thin atrophic epithelium
- Epithelial dysplasia
Describe squamous cell carcinoma in terms of:
- Its causes
- Spread
- Risk factors
Causes:
• Tobacco and alcohol are the two most important and probably account for about 75 percent of intraoral cancers
Spread:
• Carcinoma: occurs in epithelial tissue and spreads via lymph
Risk factors
• Pooling of saliva bearing carcinogens in floor of mouth
• UV exposed lip
Describe squamous cell carcinoma in terms of:
- Clinical features (where it occurs, pain, colour, and characteristics)
- Radiographic features
Unusual occurrence:
• The palate is an unusual location for carcinoma to develop
• Can occur extra-orally on the vermillion border of the lips due to sun exposure
Pain:
• Early lesions are usually asymptomatic
• Pain may be a feature of an advanced lesion
Colour:
• White patch or area of erythroplakia
Characteristics:
• A small painless ulcer/ progressing to large ulceration
• Induration: caused by invasion of the carcinoma resulting in loss of the normal elasticity
• Fixation: carcinoma infiltrating through and binding together (tethering) with surrounding tissue
Radiographic features:
• If bone involved, then bone loss
