Introduction To Oral Pathology Flashcards
What are techniques to study oral pathlogy?
Immunohistochemistry
Molecular analysis
Electron microscopy
What is a differential diagnosis?
Symptoms math more than 1 diagnosis
Social history
Tobacco, alcohol, chewing habits, occupation
History of PC?
Pain
Lesion development
Onset
Site
Size
Initiating factor
Pain relief
Associated features
Family history
Diabetes
Liver disease
Cancer
Heart attack
Stroke
Accurate lesion description?
Site
Size
Shape
Surface
Consistency
Colour
Edge
Attachment to adjacent structures
What are the next steps if you have a differential doagnosis?
Further investigation to get definitive diagnosis
What are examples of investigations?
Imaging techniques
Haematology, clinical chemistry and immunology
Microbiology
Cellular pathology
Histopahology
Molecular pathology
Sialography?
Imaging of salivary glands
How would you get samples for cellular pathology? What type of biopsy?
Exfoliating methods (brush biopsy) - not great under the microscope
Fine needle aspiration
When would you use fine needle aspiration? (Cellular pathology)
Abscess (clear) or cyst (yellow)
Incisional vs excisional biopsy?
Incisional biopsy = small part of the lesion to make a diagnosis
Excisional = removes entire lesion
When would you use a punch biopsy?
Usually on skin but can e used in the oral mucosa
What is a resection biopsy?
Take the wide border of normal tissues
Where would you place the biopsy to send to the lab?
Placed immediately in a fixative, typically neutral buffer formalin (10% formalin in phosphate buffered saline)
What does fixation of the biopsy do?
Prevents desiccation and auto lysis and hardens the tissue in preparation for laboratory processing
What do you do if. Afresh samples is required?
Damp gauze
Can be snap frozen using liquid nitrogen or dry ice (CO2)
Why use snap freeze for a biopsy?
Can check if margins are clear, even during a surgery
E.g. clear of cancer
What to place on a request form? (Sample labelling)
Patient details
Site of biopsy
Procedure (e.g. incisional versus excisional) - need to know for clear margins
Clinical history of patient
Reason for sending - histopathology
What does it mean when the lab place tissue into cassettes?
Soft tissue, remove fat and water
Will appear clear under microscope
What is the fat replaced with in th Elba? (Cassettes)
Wax (embedding in paraffin)
What sections do the lab take of teh sample to be viewed under the microscope?
5um
Now you have your slices t be viewed, what needs to be removed?
De-waxed, stained and viewed
What are the samples stained with for microscopy?
Haematoxylin and eoasin (H&E)
What colour does H stain the cell nuclei and CT? And why?
Dark pink and connective tissue glycoproteins light blue
What does eosin stain the cytoplasm and CT collagen fibres?
Cytoplasm and ct collagen fibres a reddish pink
What is the special stain for candida?
PAS
What is a specific marker for cells? IMMUNOHISTOCHEMISTRY
Antigen
Primary antibody attacks to a secondary antibody with a colour (harp polymer)
What are additional tests for individual proteins?
Immunofluorescence/ immunoperoxidase
What are additional tests for a virus?
Situ hybridisation
Hyperplasia
Proliferation of cells
Hypertrophy
Enlargement of cells
Atrophy
Decrease in number or size of cells
Metaplasia
Change to a different type of cell - benign
What is a common type of metaplasia?
Normal cells to ciliated
Ulceration
Mucosa/skin with complete loss of surface epithelium
Apoptosis
Single cell death (surrounded by viable cells)
Programmed cell death
Necrosis
Numerous cells dying in 1 area
Dysplasia
Pre-malignant
Increase in cell growth and altered differentiation, producing an overall change in archietecture of tissue
Benign tumour
Tumour that does not have the potential to invade adjacent and spread to distant bodes
Neoplasia
Loss of normal mechanism that regulates cel growth an differentiation
Benign or malignant
Malignant tumour
Invasive tumour which has the potential to invade adjacent structure and spread to distant body sites (metastasis)
Hyperkeratosis
Increased thickness of keratin layer
Hamartoma
Benign
Non-neoplastic overgrowth of tissue that is disordered in structure and is composed of tissue indigenous to the anatomical site
Hey have limited growth potential