histology Flashcards
What can be used to stain samples?
H&E
Periodic acid Schiff (PAS)
What is commonly present in hyperplastic epithelium and why?
Polymorphs
Migrate from blood vessels in the lamina propria due to chemotaxis and a stimulus which is usually bacterial or fungal
What is fungal mycelia?
Long reddish-purple stained structures in the superficial epithelium
Can also be round or oval darker stained bodies which are the fungus in the yeast phase
Where does chronic hyperplastic candidosis usually present?
The buccal commissures
What do biopsies of chronic hyperplastic candidosis usually show?
A degree of dysplasia
May show malignant change
What is chronic hyperplastic candidosis also known as?
Candidal leukoplakia
Name a main feature of epithelial dysplasia
Basal cell hyperplasia
What kind of keratosis is it if there isn’t a nucleus?
Orthokeratosis
Name 2 areas of the mouth you would be highly suspicious of malignancy in
Lateral border of the tongue
Floor of the mouth
What is epitheliotropism?
Inflammatory cells present amongst the deeper keratinocytes
Name an important histopathological finding when diagnosing malignancy
Invasion
How may mitoses make you suspicious of epithelial dysplasia?
If increased and abnormal
May increase in number, occur higher up in the epithelium than usual, or have an abnormal form eg - triradiate mitoses (3 daughter cells formed instead of 2)
What is basal cell hyperplasia?
The presence of several layers of cells of basaloid appearance
What is basal cell hyperplasia often associated with?
Drop-shaped rete pegs
What are drop-shaped rete pegs?
When the rete pegs are wider at their deepest part than they are more superficially
What 7 abnormalities in cell proliferation leads you to be suspicious of epithelial dysplasia?
Increased and abnormal mitoses
Basal cell hyperplasia
Drop-shaped rete pegs
Disturbed polarity of the basal cells or loss of cellular orientation
Alteration in nuclear/cytoplasmic ratio by area or volume
Nuclear hyperchromatism
Prominent and enlarged nucleoli
What is speckled leukoplakia and what is it also known as?
Variant of leukoplakia with both white and red areas within the lesion
Highly malignant
Aka speckled erythroleukoplakia
Describe disturbed polarity of basal cells or loss of cellular orientation
The cells in the basal layer will have no definable long axis and the nuclei will have no regular polarity
Describe normal nuclear polarity
The nuclei will have normal positions in the cell in a specific orientation, typically closer to one end than the other
What is nuclear hyperchromatism?
Nuclear staining which is abnormally intense
Name 4 signs of epithelial dysplasia relating to abnormalities of maturation and differentiation of epithelial cells
Irregular epithelial stratification or disturbed maturation
Nuclear and cellular pleomorphism
Abnormal keratinisation
Loss or reduction of intercellular adhesion or cohesion
Describe irregular epithelial stratification or disturbed maturation
The cells no longer show a proper sequence of morphological and maturational changes as they pass from the basal layer to the surface
What is epithelial stratification?
The arrangement of cells in multiple layers within an epithelial tissue
What is nuclear and cellular pleomorphism?
Nuclei and cells of different size and shape
Describe abnormal keratinisation
Keratinisation occurring below the normal keratin layer, either as individual cell keratinisation within the stratum spinosum or as disturbed maturation of groups of cells resulting in the formation of intraepithelial keratin pearls
What can loss or reduction of intercellular adhesion or cohesion be difficult to be distinguished from?
Intercellular oedema
What are rete pegs?
Anatomical structures that appear as downward projections
Characteristic feature of stratified squamous epithelium
