Oral Pathology Flashcards
What is oral and maxillofacial pathology?
A LABORATORY based clinical specialty concerned with diagnosis and assessment of diseases of the ORAL and MAXILLOFACIAL region (mouth, jaws, nose, ear, throat, neck).
3 reasons why knowing about oral and maxillofacial pathology is important?
- Diagnosis.
- Treatment.
- Prevention.
What is an incisional biopsy?
Small piece of tissue taken from a REPRESENTATIVE area of the lesion to obtain a DIAGNOSIS and influence the treatment.
What kind of specimen do you take when a patient presents with a sinister lesion but you are unsure of the diagnosis?
Incisional biopsy.
Excisional biopsy?
Clinical diagnosis is usually the definitive diagnosis, specimen removed for DIAGNOSIS and TREATMENT at the same time.
Resection?
- Usually after INCISIONAL BIOPSY.
- Surgical resection sent to pathology for further HISTOPATHOLOGICAL ASSESSMENT.
How are most specimens sent to pathology?
- FIXED with 10% NEUTRAL BUFFERED FORMALIN.
Why are specimens fixed?
- To prevent tissue breakdown.
- Crosslink proteins to preserve tissue histology.
2 reasons why a specimen may be sent fresh to pathology?
- Urgent diagnosis needed.
- Further investigations (immunofluorescent studies).
2 requirements when sending a specimen to pathology?
- Patient details on specimen pot.
- Histopathology request form.
10 things that occur once pathology receives a specimen?
- Check details on pot and request form.
- Specimen logged into system and assigned unique pathology number.
- Specimen macroscopic description and cut-up by pathologist (photos, decalcification if needed).
- All biopsy/ appropriate blocks taken from larger resection specimen and placed in cassettes.
- Processing - further fixation then dehydration of tissue in ethanol.
- Embedding - in hot paraffin wax to form tissue blocks.
- Microtome used to cut sections from tissue block - 4µm thickness.
- Sections floated in waterbath, mounted on glass slide, stained and coverslip placed.
- Slides examined by pathologist.
- (additional stains/ investigations may be required).
- Pathology report issued following examination and interpretation of the macroscopic and microscopic features.
Why is decalcification sometimes needed?
- Bones and teeth need to be softened (using acid) until they are able to be cut through with a scalpel.
What is done during the processing stage?
Processing - further fixation then dehydration of tissue in ethanol.
What happens during embedding?
Specimen embedded in hot paraffin wax to form tissue blocks.
How are sections cut from tissue blocks?
Using MICROTOME.
What thickness do the blocks cut from tissue blocks have?
4µm thickness (thickness of a single cell).
What is the most commonly used stain for sections in oral pathology?
Haematoxylin and Eosin (H and E).
3 different types of stain?
- Haematoxylin and Eosin.
- Special histochemical stains (periodic acid schiff - PAS, trichomes, gram).
- Immunohistochemistry - antibodies.
3 types of special histochemical stains?
- Periodic acid schiff - PAS.
- Trichomes.
- Gram.
4 different extra investigations to aid diagnosis?
- immunofluorescence
- in situ hybridisation
- electron microscopy
- cytogenetic and molecular genetic analysis
Hyperplasia?
The abnormal multiplication or INCREASE in the NUMBER of NORMAL cells in NORMAL ARRANGEMENT in a tissue.
Hypertrophy?
The enlargement or overgrowth of an organ or part due to an increase in size of its constituent cells.
Atrophy?
A decrease in cell size by loss of cell substance.
Metaplasia?
Reversible change in which one adult cell type is replaced by another adult cell type.
Hyperkeratosis?
Thickening of the stratum corneum.
Orthokeratosis?
The formation of an anuclear keratin layer, as in normal keratinised stratified squamous epithelium.
Parakeratosis?
The persistence of nuclei in the cells of a keratin layer.
Dyskeratosis?
Premature keratinization of epithelial cells that have not reached the keratinizing surface layer.
Acanthosis?
increased thickness of prickle cell layer
Acantholysis
the loss of intercellular adhesion between keratinocytes.
Epithelial dysplasia
alteration in differentiation, maturation and architecture of adult epithelial cells
Ulceration
mucosal/skin defect with complete loss of surface epithelium
Apoptosis
programmed cell death
Example of developmental white lesion?
Fordyce granules.
Necrosis
cell death by injury or disease
Leukoedema? what? where?
- Milky white coloration
- Usually over buccal mucosa.
- Normal variation.
3 hereditary white spot lesions?
- White sponge naevus.
- Pachyonychia congenita.
- Dyskeratosis congenita.
3 traumatic white spot lesions?
- Mechanical/ friction.
- Thermal.
- Chemical.
2 dermatological causes of white spot lesions?
- Lichen planus.
- Lupus erythematosus.
Example of normal variation white lesion?
Leukoedema
3 types of infective white lesions?
- Candidiasis.
- Oral hairy leukoplakia.
- Syphilitic leukoplakia.
Fordyce granules? What? Where?
- Ectopic sebaceous glands.
- Lips and buccal mucosa.
- Become more prominent with age.
- Developmental.
2 types of idiopathic white lesions?
- Leukoplakia.
- Proliferative verrucous leukoplakia.
2 types of neoplastic leukoplakia?
- Dysplastic lesions.
- Squamous cell carcinoma.
How is white sponge naevus inherited?
- Autosomal dominant.
- Mutations in keratins 4/13.
When does white sponge naevus present?
May be apparent in infants or not until adolescence.
What is the presentation of white sponge naevus?
- Ill defined white patches with ‘shaggy’ surface.
- Often BILATERAL.
- Any part of oral mucosa, especially BUCCAL MUCOSA.
- Other mucosa: nose, oesophagus, anogenital region.
What is a characteristic histopathological appearance of white sponge neavus?
BASKET WEAVE APPEARANCE.
due to intracellular edema of prickle and parakeratinized cells.
Histopathology of white sponge nevus?
- Hyperparakeratosis and acanthosis of epithelium.
- Basket weave apperance (intracellular edema of prickle and parakeratinized cells).
- No cellular atypia/ dysplasia.
- No inflammatory changes in lamina propria.
Treatment of white sponge nevus?
No treatment needed.
Presentation of oral hairy leukoplakia?
- White, shaggy appearance on LATERAL BORDER OF TONGUE
- Can affect other sites - can also be seen on buccal mucosa.
- Asymptomatic
What causes oral hairy leukoplakia?
- Due to EBV infection.
- Strongly associated with HIV (pathognomonic).
- Seen in immunosuppressed individuals and is some apparently healthy patients.
What is a characteristic histopathological appearance of oral hairy leukoplakia?
Band of BALLOONED PALE CELLS in the UPPER PRICKLE CELL LAYER.
Histopathology of oral hairy leukoplakia?
- Thickened, hyperparakeratotic epithelium.
- Band of ballooned pale cells in upper prickle cell layer.
- Often superadded candidal infection but without normal inflammatory response.
How is the presence of EBV in oral hairy leukoplakia confirmed?
By in situ hybridisation (ISH).
Treatment for oral hairy leukoplakia?
No treatment needed.
presentation of frictional keratosis?
Roughened white patch at site of chronic trauma.
Histopathology of frictional keratosis?
- Hyperkeratosis.
- Prominent scarring fibrosis within submucosa.
Treatment for frictional keratosis?
Resolves once the source of friction is removed.
What is lichen planus?
Common CHRONIC INFLAMMATORY DISEASE of SKIN and MUCOUS MEMBRANES.
Who is affected by lichen planus?
- Mainly affects middle aged and over.
- F > M.
What is the cause of lichen planus?
Cause unknown.
What is the pathogenesis of lichen planus?
T cell-mediated immunological damage to the basal cells of epithelium.
Relationship between oral and skin lesions in patients with lichen planus?
- Oral lesions in approximately 50% of patients with skin lesions.
- Prevalence of skin lesions in patients primarily seen for oral LP lower.
Skin presentation of lichen planus?
- Violaceous, itchy papule which may have distinctive white streaks (wickham’s striae).
- Flexor of the wrist most common site.
- Develop slowly and 85% resolve within 18 months.
What are the white streaks on lichen planus skin lesions called>
Wickham’s striae.
Oral presentation of lichen planus?
- BUCCAL MUCOSA most common site.
- Tongue, gingiva and lips may be affected.
- FOM and palate rarely affected.
- Oral LP runs a more chronic course - sometimes several years.
- Usually BILATERAL and SYMMETRICAL.
6 different presentations of oral lichen planus?
- Reticular.
- Atrophic.
- Plaque-like.
- Papular.
- Erosive.
- Bullous.
Most common oral appearance of LP?
Reticular.
Reticular LP
Most common, lace-like striae.
Atrophic LP
Diffuse red lesions resembling erythroplakia.
Plaque-like LP
White plaques resembling leukoplakia.
Papular LP
Small white papules that may coalesce.
Erosive LP
Extensive areas of shallow ulceration.
Bullous LP
Subepithelial bullae.
Characteristic histopathology presentation of LP?
- SAW-TOOTH RETE RIDGES.
- CIVATTE BODIES (basal cells undergoing apoptosis).
Histopathological presentation of LP
- Saw-tooth rete ridges.
- Dense band-like infiltrate of lymphocytes hugging epithelial/ connective tissue junction.
- Lymphocytic exocytosis.
- Civatte body (basal cells undergoing apoptosis).
- Hyperkeratosis/ hyperparakeratosis.
How do atrophic LP lesions present histopathologically?
Severe THINNING and FLATTENING of the epithelium.
How do erosive LP lesions present histopathologically?
Destruction of the epithelium, leaving fibrin-covered granulation tissue.
4 conditions that have similar histopathology to lichenoid inflammation?
- Lichenoid reaction
- Lupus erythematosus.
- Graft vs host disease.
- Lichenoid inflammation with associated dysplasia.
Treatment for LP?
If symptomatic, STEROIDS.
What are oral potentially malignant disorders?
Heterogenous group of clinically-defined conditions associated with a variable risk of progression to oral squamous carcinoma.
Lichen planus and malignant transformation?
- Not all lesions are considered to have equal risk.
- Not all lesions will undergo malignant transformation.
- Malignant change of LP 0.1-10% (likely low).
Leukoplakia?
- ORAL POTENTIALLY MALIGNANT LESION.
- A white plaque of questionable risk after excluding other known diseases.
- Can vary in thickness and surface appearance.
Risk of malignant transformation of leukoplakia?
Low.
What is proliferative verrucous leukoplakia?
PVL is a variant of oral leukoplakia that is multifactorial, persistent and progressive with a high rate of recurrence and a high risk of progression to squamous cell carcinoma.
Who is most affected by proliferative verrucous leukoplakia?
Older patients, F>M.
Oral presentation of proliferative verrucous leukoplakia?
- Gingiva, alveolar ridge, buccal mucosa, tongue, hard palate.
- Persistent, recurrent, become multi-focal.
- Begins as simple hyperkeratosis that in time becomes exophytic and wart-like.
Cause of proliferative verrucous leukoplakia?
Unknown.
2 concerns with proliferative verrucous leukoplakia?
- Difficult to completely excise.
- High risk of degenerating to ORAL CANCER –> VERRUCOUS CARCINOMA or SQUAMOUS CELL CARCINOMA.
Histology of proliferative verrucous leukoplakia?
Hyperplastic lesion, hyperkeratosis, often minimal dysplasia.
3 examples of infective red patches?
- Periodontal disease.
- Median rhomboid glossitis.
- HIV gingivitis.
2 dermatological disorders that can manifest as red oral patches?
- Erosive lichen planus.
- Discoid lupus erythematosus.
2 idiopathic examples of red patches?
- Erythroplakia.
- Geographic tongue.
2 neoplastic red patches?
- Dysplastic lesions.
- Squamous cell carcinoma.
Presentation of median rhomboid glossitis (3)?
- Rhomboid red patch on midline of posterior aspect of anterior 2/3rds of dorsal tongue.
- Asymptomatic.
- May be a ‘kissing lesion’ - reciprocal lesion on palate opposing tongue.
Aetiology of median rhomboid glossitis?
Most cases associated with candida.
How is median rhomboid glossitis diagnosed?
- Usually diagnosed CLINICALLY (no need for biopsy).
- Sometimes get biopsy.
Histopathology of median rhomboid glossitis?
- Loss of lingual papillae.
- Thickened epithelium.
- Parakeratosis and acanthosis.
- CANDIDAL HYPHAE and neutrophils in parakeratin.
- Chronic inflammatory infiltrate in connective tissue.
Treatment for median rhomboid glossitis?
Antifungal medication.
What stain is used to highlight candida?
periodic acid Schiff (PAS).
What is erythroplakia?
- A red patch that cannot be characterized clinically or pathologically as another definable lesion.
- An ORAL POTENTIALLY MALIGNANT DISORDER.
Presentation of erythroplakia?
- Red ‘velvety’ appearance, smooth or nodular.
- Most frequently seen on palate, FOM and buccal mucosa.
- Less common than leukoplakia.
What is erythroleukoplakia?
- Speckled leukoplakia.
- Has both leukoplakia and erythroplakia components.
- ORAL POTENTIALLY MALIGNANT DISORDER.
Malignancy and erythroleukoplakia and erythroplakia?
- HIGH likelihood of malignant transformation.
- Greater than 90% will be SEVERE DYSPLASIA or CARCINOMA.
Exogenous sources of oral pigmentation? (5)
- Superficial staining of mucosa (foods, drinks, tobacco).
- Black hairy tongue.
- Foreign bodies (ex. amalgam tattoo).
- Heavy metal poisoning.
- Some drugs, NSAIDs, antimalarials, chlorhexidine.
What results in black hairy tongue?
Papillary hyperplasia + overgrowth of pigment producing bacteria.
Who is most affected by black hairy tongue? Treatment?
- Much more common in SMOKERS.
- No IMMEDIATE treatment but good OH should help reduce appearance.
What causes amalgam tattoo? Presentation?
- Amalgam introduced into SOCKET/ MUCOSA during treatment.
- SYMPTOMLESS blue/black lesion.
- May be seen on radiograph.
Histopathology of amalgam tattoo?
Pigment dispersed in connective tissue as fine black/ brown granules.
Treatment for amalgam tattoo?
- None required.
- Patient may request removal for aesthetics.
- If not seen on radiograph, may be excised to confirm diagnosis.
9 ENDOGENOUS causes of oral pigmentation?
- Normal variation in pigmentation similar to that seen in skin.
- Melanotic macule.
- Pigmented naevi.
- Peutz_Jeghers syndrome.
- Smoker’s melanosis.
- HIV infection.
- Manifestation of systemic disease (ex. addison’s disease, malignancy).
- Mucosal melanoma.
- melanotic neuroectodermal tumor of infancy.
Pigmented naevi?
Developmental lesions with proliferation of melanocytes.
Peutz-jeghers syndrome?
Multiple pigmented lesions on skin/mucosa, LIPS, tongue, palate, buccal mucosa, intestinal polyposis.
Smoker’s melanosis?
pigmentary incontinence.
HIV infection?
numerous melanotic macules in some individuals.
Melanotic macule presentation?
- Well defined small brown/black lesions.
- Buccal mucosa, palate and gingivae.
Cause of melanotic macule?
Due to INCREASED ACTIVITY OF MELANOCYTES.
- Benign.
Treatment for melanotic macule?
frequently excised to confirm diagnosis and exclude melanoma.
Histopathology of melanotic macule?
- Increased melanin pigment in basal keratinocytes, NOT increased number of melanocytes.
- Melanin pigmentary incontinence in connective tissue.
What is mucosal melanoma?
MALIGNANT NEOPLASM of mucosal MELANOCYTES.
Most common sites for mucosal melanoma in the head and neck? (2)
- Nose.
- Maxillary sinus.
Presentation of mucosal melanoma (7)?
- Primary intraoral mucosal melanoma is rare but can occur.
- HARD PALATE and MAXILLARY GINGIVAE most common intraoral sites.
- Dark brown, black or red.
- Typically ASYMPTOMATIC at first.
- May remain unnoticed until pain, ulceration, bleeding or a neck mass.
- Regional lymph node and blood-borne metastases are common
- Typically very advanced at presentation
Who does mucosal melanoma most often affect?
40-60 years.
Progression of mucosal melanoma?
- Typically very advanced at presentation.
- Very invasive, metastasize early.
- Prognosis is POOR.
Aetiology of mucosal melanomas?
Unknown.
Histopathology of mucosal melanoma?
- Pleomorphic neoplasms, cells appear epithelioid or spindle-shaped.
- Amount of melanin pigment is variable and may be absent.
What special histopathological investigation can be used to help DIAGNOSE mucosal melanoma?
Immunohistochemistry using specific markers for malignant melanocytes.
Treatment for mucosal melanoma (3)?
- SURGICAL RESECTION.
- Adjuvant radiotherapy.
- Immunotherapy.
Who is most often affected by melanotic neuroectodermal tumor of infancy?
- Very rare.
- most < 1 years old.
- M >F.
Presentation of melanotic neuroectodermal tumor of infancy?
- Locally aggressive, rapidly growing pigmented mass.
- Most often ANTERIOR MAXILLARY ALVEOLUS.
Origin and pathogenesis of melanotic neuroectodermal tumor of infancy?
- ?neural crest cell origin.
- Pathogenesis is unknown.
histopathology of melanotic ectodermal tumor of infancy?
Tumor comprises 2 types of cells:
- Neuroblastic.
- Pigmented epithelial cells.
treatment of melanotic neuroectodermal tumor of infancy?
- Complete local excision is treatment of choice.
- Tumor of uncertain malignant potential
- Can recur.
- Small number do metastasise.
what is an ulcer?
Localized surface defect with LOSS OF EPITHELIUM, exposing underlying INFLAMED CONNECTIVE TISSUE.
infective causes of oral ulceration?
- Bacterial.
- Fungal.
- Viral (HSV, VZV, CMV, Coxsackie).
5 traumatic causes of oral ulceration?
- Mechanical.
- Chemical.
- Thermal.
- Factitious injury.
- Radiation.
Drugs that can cause oral ulceration? (2)
- NSAIDs.
- Nicorandil.
Idiopathic causes of oral ulceration (1)?
Recurrent aphthous stomatitis.
3 systemic disease causes of oral ulcers?
- Hematological disease.
- GI disease.
- HIV.
3 dermatological disease causes of oral ulcers?
- Lichen planus.
- Discoid lupus erythematosus.
- Immunobullous diseases.
3 neoplastic causes of oral ulcers?
- Oral squamous cell carcinoma.
- Salivary gland neoplasms.
- metastases.
Histopathology of ulcers?
Most ulcers will show NON SPECIFIC FEATURES OF ULCERATION:
- loss of surface epithelium.
- Inflamed fibrinoid exudate.
- Inflamed granulation tissue.
How do vesiculobullous lesions usually present?
- vesicle is a small blister.
- Bulla is a blister >10mm.
- Presents as ORAL ULCERATION following rupture of vesicles/ bullae.
What are immunobullous disorders?
- Subset of vesiculobullous disorders.
- AUTOIMMUNE diseases in which autoantibodies against components of skin and mucosa produce BLISTERS.
2 ways to classify disorders which result in vesicles/ bullae histologically?
Based on the LOCATION of the bulla:
1. Intraepithelial.
2. Subepithelial.
2 types of intraepithelial bullous disorder?
- Non -acantholytic (death and rupture of cells, ex. viral infection as HSV).
- Acantholytic (desmosomal breakdown).
Give an example of intraepithelial non- acantholytic pathogen and diseases (2)?
- HERPES SIMPLEX VIRUS.
- Primary herpetic stomatitis.
- Herpes labialis.
Primary herpetic stomatitis?
Intra epithelial, non acantholytic vesiculobullous condition.
herpes labialis?
Intra epithelial, non acantholytic vesiculobullous condition.
How do intraepithelial, NON acantholytic pathogens cause ulceration (4)?
- Virus targets and replicates within epithelial cells.
- Leads to cell lysis.
- Groups of infected cells breakdown to form vesicles within the epithelium.
- Infected cells infect nearby normal cells and an ulcer forms when the full thickness of the epithelium is involved and is destroyed.
Example of intra epithelial acantholytic lesion?
PEMPHIGUS