Biopsy Flashcards
What is a biopsy ?
this is the removal of part, or all, of a lesion to enable histopathological examination and definitive diagnosis of the lesion
List some indications for a biopsy
- any lesion that persists for more than 3 weeks and no cause can be found
- an inflammatory lesion which does not resolve following the removal of the cause e.g. sharp tooth
- lesions which interfere with function e.g. epulis or fibro-epithelial polyp
- all red patches
- most white patches, especially if speckled or non- homogenous for which no cause is found
- any lesions which possesses malignant signs e.g. induration (hardness), fixation to underlying tissues, rapid growth, bleeding or ulceration
Where should LA be placed when taking a biopsy sample?
it should be placed away from the site as it could cause damage to the specimen
State some criteria required for a biopsy
- should include a portion of clinically normal tissue
- site of the sample should be from an area that is most representative of the rest of the lesion
- if the lesion contains regions of varying clinical appearance, multiple biopsies should be undertaken
- areas of necrosis or ulceration should be avoided as they are limited diagnostic use
What are the types of biopsies are mainly performed in the oral cavity?
- excisional
- incisional
Give examples of clinically diagnosed lesions that are not suitable for biopsy in a general dental practice and require referal to hospital
- chronic ulcer or SCC
- erythro/leukoplakia
- bullous lesions e.g. pemhigoid
- granulomatous disease e.g. crohns
- minor salivary gland tumour
- hard tissue lesions
- erosive lichen planus
Give examples of clinically diagnosed lesions that are suitable for biopsy in a general dental practice
- lichen planus-reticular/striated requires surgical experience
Exicisonal lesions are more amenable to what kinds of lesions?
small benign lesions
<1cm
Give examples of small benign lesions suitable for excisional biopsy
- fibro-epithelial polpys
- pyogenic granuloma and epulis
- fibroma
- papilloma
- hyperplastic tissue
- mucocele
What is a mucocele ?
common lesion of the oral mucosa that results from an alteration of the minor salivary glands due to mucous accumulation causing limited swelling
Incisional biopsies are more amenable to what types of lesions?
large or suspicious lesions
Give examples of large/suspicious lesions that are suitable for incisional biopsies
- chronic ulcer
- squamous cell carcinoma
- leuko/erythroplakia
- lichen planus
- bullous lesions
Give an example of a lesion that is amenable/suitable for a punch biopsy
bullous lesion
Give examples of lesions that are suitable for fine needle aspiration biopsies
- soft tissue masses prior to surgical exploration
- bony cysts prior to surgical exploration
in nodes and salivary glands
What is an excisional biopsy ?
one that removes the entire lesion and a small margin of normal tissue
The nature of an excisional biops makes it both _______ and _________
- curative and diagnostic
Outline how you would perform an excisional biopsy of a fibro-epithelial polyp
- suture can be placed beneath the lesion with a loose knot; held with an artery clip (ensure suture is placed beneath the lesion and not through the area of interest) - this is an optional step
- make an elliptical incision around the base of the lesion including a small margin of tissue around the lesion
- as fibro-epithelial polyps are superficial , sharp dissection is then used to seperate the lesion from the underlying tissues
- closure is achieve with superficial, simple interrupted sutures
Video helped with further understanding
Outline how you would perform an excisional biopsy of a mucocele
- suture can be placed beneath the lesion with a loose knot; held with an artery clip (ensure suture is placed beneath the lesion and not through the area of interest) - this is an optional step
- make an elliptical incision around the base of the lesion including a small margin of tissue around the lesion
- as mucoceles are more fragile/deeper, blunt dissection is then used to seperate the lesion from the underlying tissues
- closure is achieve with superficial, simple interrupted sutures
What is the benefit/purpose of placing a suture beneath the lesion?
this is to apply tension to the lesion without crushing any artefact which may arise if tissue forceps are used to steady the tissue
Briefly outline a summary of information that should be noted on the pathology form for a biopsy
- patient details; DOB, name, gender, race
- history of lesion
- MH detailing drugs
- SH: smoking, alcohol
- clinical appearance of lesion
- associated pathology or restorations
- investigations with results
- biopsy type
- labelled diagram
- clinical diagnosis
- consultants (dentists) name and address
What types of sutures can be used to close a wound following excisional biopsy ?
- resorbable (vicyrl) are the most often placed
- black silk suture can also be placed
When is an incisional biopsy indicated?
- when complete removal of the lesion would be difficult e.g. lichen planus or a diffuse white patch
- if clinical diagnosis is uncertain
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What are the requirements of an incisional biopsy?
- deep enough to include the basement membrane and underlying connective tissue (at least 3-4mm)
- a general guide is as follows- the length should be 3x the width of the biopsy
- must include normal tissue together with abnormal to act as a reference
What does the length of an incisional biopsy depend on?
largely depends on the area that has been chosen to be biopsied
Briefly describe how an incisional biopsy would be carried out
- elliptical incision made to the required depth ad the sample of tissue is excised
- one end of the ellipsed incision is held and lifted with tissue forceps or a holding suture (ensure the forcep or holding suture is held away from the pathology) and then a sample is carefully dissected out
- primary closure is achieved with sutures
What is an artefact?
this is something that alters the appearance of a sample tissue when mounted on a microscopic slide and can result from crush injuries from forceps, haemorrhage, fragmentation and splits
What is the most common artefact observed following biopsies perfromed by a GDP?
crush injuries
It is also significantly more than crush injuries found in biopsies performed by oral and maxillofacial surgeons (thhe same was true for haemorrhage artefacts)
State some causes of crush artefacts in biopsies
- grasping soft tissue with forceps
- using a suture for traction and tying the knot over a lesion too tightly
- using a blunt scalpel blade
What is usually the cause of haemorrhage artefacts ?
it is usually the result of intralesional injection of LA
It can be avoided by infiltrating LA away from the area of interest or a regional block
What is the purpose of a labelled diagram on the pathology form?
A labelled diagram on the pathology form can show position and size of lesion (indicating where lesion was taken from)
What clinical details should be noted following an incisional biopsy?
- size
- shape
- duration
- changes
- colour
- texture
- radiographic appearance
- relevant MH or DH
- clinical diagnosis by surgeon where possible
State the instrumentation required for a soft tissue biopsy
- LA
- scalpel with No.15 blade
- sharp-pointed scissorys
- small clip- mosquito clip
- fine tissue forceps
- needle holders and suture material
- sterile gauze and saline
- biopsy pot containing 10% formalin
- pathology form
Some samples need to be sent fresh to the pathologist. Give an example of this and state a brief explanation why.
- vesiculo-bullous disorder
this is because these samples require immunofluorescent techniques
What is the ideal way to manage samples post-operatively?
- placed immediately into a sealable container with 10% neutral buffered formalin
- there should be 10x more fixative than specimen
If in doubt about the transport medium to use, what medium is acceptable in the meantime?
normal saline
How should packages containing specimen be sent from the practice to the lab?
- container should be surrounded with absorbent material to absorb leakages
- placed in a sealed plastic bag and in turn placed into a rigid box
- box should be labelled “PATHOLOGICAL SPECIMEN” and “fragile- handle with care”
What are the advantages of performing simple biopsies in general practice for the patient ?
- confidence of having a known and trusted clinician perform the procedure
- less waiting time for the procedure and results
- less travelling
What are the advantages of performing simple biopsies in the general practice for hospitals?
- reduction in referrals and therefore waiting lists
