Oral pathology/medicine/periodontology Flashcards
How thin are the sections cut of the tissue embedded in wax?
Microtome used to cut sections of 4um thickness
What are the three most common stain types?
- Haematoxylin and Eosin (H&E) routinely used
- Special histochemical stains e.g. Periodic Acid - Schiff (PAS), Trichromes, Gram
- Immunohistochemistry - antibodies
Hyperplasia vs hypertrophy
Hyper = increase
Plasia —> number of cells increased
Trophy —> size of cells increased
Metaplasia
Reversible change in which one adult cell type is replaced by another adult cell type
Hyperkeratosis
Thickening of the stratum corneum
Ulceration
Mucosal/skin defect with complete loss of surface epithelium
White lesions: developmental
fordyce granules
White lesion: normal variation
Leukoedema (stretch mucosa and it should disappear)
White lesions: Hereditary
White sponge naevus, Pachyonchia congenita, Dyskeratosis congenita
White sponge naevus
no tx required - thickened epithelium with marked hyperparakeratosis (mutation in keratin)
“basket weave” appearance
Pachyonchia congenita (genetic keratin mutation)
Dyskeratosis congenita (genetic keratin mutation)
Lichen planus
Lupus erthematosus
Leukoplakia
Leukoplakia
What causes Oral Hairy Leukoplakia?
Epstein-Barr virus (strongly associated with HIV infection in many cases)
oral hairy leukoplakia
What are the key pathological features of oral hairy leukoplakia?
Tx of oral hairy leukoplakia
none needed
Histopathology of frictional keratosis
hyperkeratosis
prominent scarring fibrosis within submucosa
Lichen planus description
Common chronic inflammatory disease of skin and mucous membranes —> if effected by skin lesions then 50% chance of having oral lesions too.
Aetiology unknown
What are the clinical features of lichen planus?
Bilateral and often symmetrical
What is the pathogenesis of lichen planus?
T cell-mediated immunological damage to the basal cells of the epithelium
Histopathology of lichen planus
What’s important to remember about the histopathology of lichen planus?
It is similar to lichenoid reaction to drugs, lupus erythematosus, etc
Management of lichen planus
manage symptoms - steriods occasionally
OMPD
Oral Potentially Malignant Disorder
What are some OPMDs?
Leukoplakia
white patch with questionable risk
LOW risk of malignant change
Proliferative Verrucous Leukoplakia
white patch with HIGH risk of progression to SCC
begins as a simple hyperkeratosis that in time becomes exophytic and wart-like
Median Rhomboid Glossitis
midline red patch
unknown - often associated w candida
Histopathology of median rhomboid glossitis
Treatment of median rhomboid glossitis
anti fungal medication
Erythroplakia
Erythroleukoplakia (speckled leukoplakia)
Cause of black hair tongue?
Papillary hyperplasia + overgrowth of pigment-producing bacteria
melanotic macule
Histopathology of melanotic macule
NOT an increased number of melanocytes
Melanoma - malignancy
Melanotic Neuroectodermal Tumour of Infancy
Left - aphthous ulcer
Right - traumatic ulcer
How can you differentiate between aphthous ulcer and traumatic ulcer?
Clinically - NOT histopathologically
Histopathology of ulcers
Histopathology of ulcers
Blister vs bulla
when the blister is greater than 10mm = bulla
Vesicles/bullae can be…(2)
1.Intrapithelial
2. Subepithelial
What are the two types of intraepithelial vesicles?
Non-acantholytic (death and rupture of cells)
Acantholytic (desmosomal breakdown)
Herpes simplex virus in primary herpetic stomatitis and herpes labialis is an example of what type of vesicle?
Intraepithelial non-acantholytic (CELL DEATH)
Pemphigus (and Pemphigus vulgaris) are caused by an autoimmune disease resulting in what type of vesicles?
Intraepithelial acantholytic (desmosomal breakdown)
Treatment of pemphigus vulgaris
steroids
Histopathology of pemphigus vulgaris
Histopathological examination of pemphigus vulgaris
Direct immunofluorescene
Mucous membrane pemphigoid (subepithelial vescicles)
Autoimmune disease
Histopathology of mucous membrane pemphigoid
Direct immunofluorescene investigation
Epidermolysis Bullosa Acquisita (uncommon, autoimmune blistering dermatitis with subepithelial bullae)
Epidermolysis Bullosa
(formation of skin bullae which heal with scarring 3 variants; simplex, junctional and dystrophic)
Angina bullosa haemorrhagica
(spontaneous blood-filled bullae, bursts to form ulcers and heal uneventfully - secondary to trauma??)
Oral submucous fibrosis
an oral potentially malignant disorder —> HIGH risk of malignant transformation
WHO 2024 classification of epithelial dysplasia
Oral epithelial dysplasia (OED) is a spectrum of
architectural and cytological epithelial changes resulting from accumulation of genetic alterations, usually arising in a range of oral potentially malignant disorders (OPMD) and indicating a risk of malignant transformation to squamous cell carcinoma (SCC).
Histological features of epithelial dysplasia p
- funky shapes and sizes of cells and nuclei (pleomorphism)
- Nucleus getting bigger inside the cell (nuclei-cytoplasmic ratio effected)
- Darkened colouring of cells/nuclei (nuclear hyperchromatism)
- basal cell hyperplasia with loss of polarity
- abnormal keratinisation (dyskeratosis)
- drop-shaped retepegs i.e. wider at their deepest part
dysplasia; mild, moderate and severe
mild = bit disorganised
moderate = reaches suprabasal cells
severe = affects full thickeners of epithelium
How is epithelial dysplasia different to cancer (SCC)?
All the features of dysplasia may be seen in oral
squamous cell carcinoma, however in dysplasia
the atypical cells are confined to the
surface epithelium
In squamous cell carcinoma, the atypical cells
invade into the underlying connective tissue.
What percentage of oral cancers are SSCs?
> 90%
5 year survival rate for oral cancer is
55%
Highest risk factor for oral cancer
SMOKING.
TNM classification of malignant tumours
T- extent of primary Tumour
N- absence or prescence and extent of regional lymph Node metastasis
M- absence or presence of distant Metastasis
T1N0M0, T4aN2aM1
Which cancer is worse?
Each component is given a number, the higher the number the
more extensive the disease, poorer prognosis.
therefore = T4aN2aM1
Definition: Abscess
Abscess —> “cess”= puss; collection of pus i.e. infection.
Cyst—> sac of fluid encased partly or wholly by epithelial cells, painless unless grows too big
Histopathology: Acute periradicular periodontitis
Neutrophil, vascular dilation, neutrophils, oedema
Histopathology: acute periapical abscess
Central collection of pus (neutrophils, bacteria, cellular debris)
Adjacent zone of preserved neutrophils
Surrounding membrane of sprouting capillaries and vascular dilation and occasional fibroblasts (granulation
tissue)
histopathology: chronic periradicular periodontitis
histopathology: periapical granuloma
histopathology: periocoronitis
Acute and chronic inflammatory changes including
oedema, inflammatory cells, vascular dilation, fibrotic
connective tissue
What does a cyst have to be to be classified as an odontogenic cyst?
Derived from epithelial residues of tooth-forming organ
What are the two types of odontogenic cysts?
inflammatory
developmental
What are the four layers of the enamel organ
Development: what forms pulp?
ectomesenchymal cells
What are the types of inflammatory odontogenic cysts?
1 Radicular cyst
2 inflammatory collateral cyst (not necessarily from endodontic cause but by some breach of the oral mucosa which causes inflammation and proliferation of epithelial cells and thus a cyst forming - pericornitis)
What is the most common type of jaw cyst?
Radicular cyst (55%)
- mainly in the maxilla
What does this histopathology show?
Radicular cyst
Marsupialisation
Marsupialization is a surgical procedure used to treat large cysts by creating an opening in the cyst wall and suturing the edges to the surrounding tissue. This allows the cyst to drain and shrink gradually over time, preserving surrounding structures and avoiding complete excision, particularly in large or difficult-to-remove cysts.
Enucleation vs marsupialisation of cysts
“enucleation” means completely removing the entire cyst lining, while “marsupialization” involves creating a pouch-like opening in the cyst wall, draining its contents, and then suturing the edges to the surrounding tissue, essentially turning the cyst into a “pocket” that gradually shrinks over time
Odontogenic Keratocyst (OKC)
Developmental cyst
3rd most common jaw cyst
MANDIBLE mainly (80%)
Where do OKCs arrise from?
Remnants of the dental lamina (Glands of Serres)
Why might OKCs be diagnosed late?
Symptomless, anterior-posterior expansion means they don’t show up and a swelling necessarily.
Neoplastic meaning
New growth
What syndrome may cause a patient to develop multiple odontogenic keratocysts at a young age?
Nevoid Basal Cell Carcinoma Syndrome