Principles of Tissue Biopsy in Oral and Maxillofacial Surgery Flashcards
what is the definition of a biopsy
an exam of tissue removed from a living person to discover the presence, cause, or extent of cause
what are biopsies important for
an important diagnostic tooth for the diagnosis of lesions ranging from peri-apical lesions to malignancies in the oral cavity
what are the indications for biopsy
- persistent hyperkeratosis changes in tissue
- any persistent swelling, either visible or palpable beneath relatively normal tissue
- lesion that interferes with local function (fibroma)
- bone lesions identified by radiographic finding
- any lesion that has the characteristics of malignancy
- any suspicious lesion persists for more than 2 weeks with no apparent etiology basis
what are characteristics of lesions that raise the suspicion of malignancy
- erythema
- ulceration
- growth rate
- bleeding
- induration
- fixation
what is erthryoplakia
lesion that is totally red or has speckled red appearance
describe the ulceration that raises the suspicion of malignancy
presents an ulcer and the lesion has persisted more than 2 weeks
describe the growth rate that raises the suspicion of malignancy
rapid growth
describe the bleeding that raises the suspicion of malignancy
bleeds on gentle manipulation
describe the induration that raises the suspicion of malignancy
lesion and surrounding tissue is hard to the touch
describe the fixation that raises the suspicion of malignancy
lesion feels attached to adjacent structures
what needs to be done before the biopsy
- health history
- history of the lesion
- clinical exam
- imaging studies
- lab investigation
- biopsy (hist-pathological exam)
what systemic disease might cause a pathologic condition in the head or neck region
- browns tumors of hyperparathyroidism
- hairy leukoplakia- HIV pt
what questions do you ask in the history of the lesion
- duration
- changes in size and rate of change
- changes in the character of the lesion - lump to ulcer
- changes in color
- pain
- anesthesia
- swelling or tenderness of adjacent lymph nodes
- associated systemic symptoms such as: fever or dysphagia
the clinical exam should include when possible:
- inspection
- palpation
what should be looked for on clinical exam
- the anatomic location of the lesion/mass
- the size and shape of the lesion/mass
- single vs multiple lesions
- the surface of the lesion
- the color of the lesion
- the sharpness of the boundaries of the lesion
- the consistency of the lesion to palpation
- presence of pulsation
- lymph node examination
a radiolucency with defined borders is often a:
cyst
a ragged radiolucency will often be a more _____ lesion
aggressive
apart from regular xrays, whenever necessary it is important to use more advanced imaging modalities such as:
- CBCT
- Conventional CT
- MRI
- ultrasound
if a systemic disease is suspected, the appropriate lab investigations should be pursued ____ performing a biopsy procedure
before
hyperparathyroidism can cause what elevation in the serum calcium level
10/5 to 11.6 mg/dl
what is a normal serum calcium level
8-10 mg/dl
hypercalcemia is defined as a serum calcium level greater than:
10.5mg/dl
what are the types of biopsies
- excisional biopsy
- incisional biopsy
-bone biopsy - punch biopsy
- fine needle aspiration biopsy
what is an excisional biopsy
- total excision of a lesion for microscopic study
- removal of the entire lesion
- a perimeter of normal tissue surround the lesion is also excised to ensure total removal
-constitute definitive treatment
when are excisional biopsies done
slow growing lesions that appear benign on clinical exam
what is the principle of excisional biopsy
the entire lesion along with 2-3 mm of normal appearing surrounding tissue is excised
when are incisional biopsies used
some lesions are too large to excise initially without having established dx or are of such a nature that excision would be inadvisable
what is the use of incisional biopsy
for large lesions or when there is a suspicion of malignancy
what are the principles of incisional biopsy
- representative ares of lesion should be incised in wedge fashion
- selected in an area that shows complete tissue changes (the lesion extends into normal tissue at the base and/or margin of the lesion)
- necrotic tissue should be avoided
- taken from the edge of the lesion to include some normal tissue
- a deep, narrow biopsy rather than a broad shallow one
describe aspiration
- the use of a needle and syringe to penetrate a lesion for aspiration of its content
- an 18 gauge needle is connected to a 5 or 10 mL syringe
- the tip of the needle may have to be repeatedly repositioned to locate a fluid center
what are the indications for aspiration
- should be carried out on all lesions throught to contain fluid or any intraosseous lesion before surgical exploration
- a fluctuant mass in the soft tissues should also be aspirated to determine its contents
- any radiolucency in the bone of the jaw should be aspirated to rule out a vascular lesion that can cause life threatening hemorrhage
any intraosseous lesion like tumors, cysts, infections (osteomyelitis) diseases like fibro osseous lesions require a _____ biopsy procedure
bone
bone and other hard tissues that contain calcium takes _____ for processing in the histopath lab
extra time
what is a punch biopsy
a surgical instrument is used to punch out a representative portion of tissue
describe the punch biopsy procedure
- the punch comprises a circular blade attached to a plastic handle, diameters of two to ten millimeters are available
- the punch removes a core of tissue the base of which can be simply and atraumatically released using carving scissors
- the resultant wound may not require suturing if using the smaller diameter punches
what is the use for fine needle aspiration biopsy
to biopsy deep seated lesions
what is the technique for fine needle aspiration biopsy
uses very thin needle and a syringe to take out a small amount of fluid and very small pieces of tissue from tumor/mass
in cases where the tumor is deep seated then you can use:
CT scan guided or ultrasound guided fine needle aspiration
what are the advantages and disadvantages of the fine needly aspiration biopsy
- advantages: does not require incision on the skin, biopsy results available same day
- disadvantages: needle cannot remove enough tissue for diagnosis
what are the considerations with anesthesia and biopsies
- block local anesthesia techniques are employed when possible
- the anesthetic solution should not be injected within the tissue to be removed, because it can cause artificial distortion of the specimen
- if necessary infiltration of local anesthesia may be used locally but the solution should be injected at least 1 cm away from the lesion
what should be used as tissue stabilization
- tongue or soft palate: heavy retraction sutures
- lip: assistants finger pinching the lip on both sides of the biopsy area
how should you achieve hemostasis
- avoid suction device
- gauze wrapped over the tip of the low volume suction device
- simple gauze compression
for dx the excised specimen needs to be:
fixed to stop tissue autolysis prior to the sample reaching the pathology lab
what is the solution of choice for specimen care
10% formaling fixative (neutral, phosphate buffered)
specimen must be _____ in the solution
totally immersed
care should be taken to be sure that the tissue has not:
become lodged on the wall of the container above the level of the formalin to present specimen from becoming dry and unfixed
what type of tissue should be chosen in lichenoid reactions
non erosive lesional tissue - adjacent normal tissue is not required for such lesions
why is sampling an erosive area not a good idea
it will show non specific inflammatory changes associated with ulceration and will not aid in the dx
for suspected vesiculo-bullous disorders the site of the biopsy should be:
adjacent to bulla where epithelium is still intact
what solution should suspected vesiculo bullous lesions be in
michel’s transport medium for direct immunofluorescence
what is the direct immunofluorescence stain for intra oral pemphigus
immunoglobulin G deposited in the intercellular regions of the keratinocytes of the epithelium
in the cause of soft tissue biopsies how long does the result take
1 week
how long does a mineralized sample such as bone or tooth take to get back and why
it may require decalcification before it can be processed. the time for decalcification will vary according to the size and consistency of the specimen as well as the methods employed by a particular lab
- can take 2-3 weeks
