Om and biopsy (OS) Flashcards
When do you refer to OM?
Potentially malignant leisons:
1-Red/white patches
2-Erosions/ ulcers
3-Vesiculobullous lesions
4-Burning mouth syndrome
5-Facial pain: non-odontogenic origin
6- Xerostomia: Salivary gland biopsy foe sjoren’s syndrome
What is a biopsy?
The removal of tissues for histopathological examination
1- mucosa
2-bone
3-curettage of cyst lining or contents: sometimes when you extract a tooth and have a cyst attached you can send it to biopsy
What types of biopsies are there by technique?
1-Excisional: whole lesions
2- Incisional: part of lesions
exfoliative cytology
aspirational (FNAC)
labial gland biopsy
When would you do a excisional biopsy?
you would excise the whole way around +1mm:
Small, benign lesions
normal tissue included
special investigation=treatment
What benign lesions could you get?
1-Mucocele: Swelling under the mucus due to blockage of the salivary duct, would excise it and the gland associated, you should warn the patient of a scar and numbness of the region temporarily
2- Denture Hypalsia: due to wearing a ill fitting denture and not removing it
3- epulous: swelling on the gum, pyogenic granulation a soft tissue granulation lesion. Due to a ledge in a filling
4- leaf fybroma: ill fitting denture tissue development leaf shape
How would you preform a incisional biopsy?
Removal of a representative portion of lesion
multiple specimens may be necessary (mapping biopsies)
need reasonable size of tissue
What is a endophytic and a exophytic lesion?
Endo: growing inwards
Exo: growing outwards
What instruments would you use to take a biopsy?
> LA
Tooth tissue forceps
in cases of increased bleeding you can use a diathermy to close the site of biopsy
a Punch biopsy you can use on small areas
Co2 Laser: you can use this when excision of extensive lesions, this will directly close up the wound directly but cannot be used for biopsy
*cryotherapy: which is freezing of the lesion, this is used on vascular lesions called haemangiomas
What is the biopsy placed in after excision?
Formal saline and the proteins deproteinise and would cause it to shrink
When using the laser what cautions should you adopt?
It is simple and straight forward to use but we must protect the patient eyes so that the laser does not bounce off metal and harm the patient, use plastic instruments and undergo training
What techniques are used for a good Biopsy?
1-Choose most appropriate site: worst looking part but convenient and pt will tolerate
2- LA infiltration: for pain and haemostasis
3-Regular ellipse of tissue of a reasonable size: you have to orientate it by passing different colour sutures. or pin it by a cardboard board.
4-wedge of tissue: take all the underlying soft tissue not just mucosa
5-atraumatic technique: be careful with the forceps
6-haemostasis: you might have to use diathermy
7-primary closure when possible
What problems can happen with a biopsy?
1-Inappropriate specimen: you might have to repeat
2-specimen too small or macerated
3-cant orientate specimen
4-tissues distorted by diathermy or LA
5-lab not informed of need for frozen section: you need to phone in advance
6-lack of clinical detail on form: HPC, Size, colour, texture, ulcerated, indurated and risk factors
7-specimen gone up aspirator!
What is meant by a frozen section and what are its benefits?
> the section is placed on ice instead of formal saline and then taken to the la and put in liquid nitrogen, this is only used for cancerous and vesicular bullous lesions
Allow rapid diagnosis of malignancy
exclude carcinoma at time of surgery
result within 1 hour
difficult to assess dysplasia with confidence
required for direct immunofluoresence
What is exfoliative cytology?
> Removal of surface cells by scraping with a spatula or cytobrush
widely used in cervical cancer screening
research continues in its application in diagnosis of oral carcinoma (cytokeratins, nuclear and cell area)
What is fine needle aspiration cytology?
> Determines whether lesion is solid or cystic/ fluid filled
simple to perform – just insert needle into the area/ swelling
interpretation difficult but experienced cytopatholgists >have high success rate
cyst contents can undergo further tests e.g microbiology, protein electrophoresis
Very useful with lumps in the parotid glands and neck lumps to determine whether the lump is a tumour
