Ch 20 Biopsy princples Flashcards
What the 2 main types of cutting needles for needle-core biopsies?
Tru-Cut needles - Hand powered and automated version
Franklin-silverman needle - split needle design
To waht depth should cutting needled be placed into the tissue?
How should the sample be removed?
At least 1.5cm into tissue of interest
Sample removed with a 25g needle
What are the three main aspiration needle-core biopsy needles?
Menghini
Klatskin
Jamshidi
Menghini has an external bevel whereas Klatskin and Jamshidi have an internal bevel allowing a larger sample with no increased risk
What is a vacuum-assisted needle-core biopsy device?
Similar to Tru-Cut but with the addition of a vacuum
How often to needle-core biopsies get a diagnosis?
How often does thi diagnosis agree with surgically obtained biopsies?
TruCut is diagnostic in 40-97%
Agrees with surgical biopsy in 54-94%
What range of sizes are punch biopsies available?
1-8mm
What is the recommended location when obtaining an incisinal biopsy?
At the junction of mass and normal adjacent tissue
- Must consider spread of disease to uninvolved tissue
- Avoid the periphery in bone lesions as this will most likely sample reactive periosteum
bone: Radiographs can be helpful to identify an appropriate biopsy site
type of laparoscopic biopsy
A - Laparoscopic cup biopsy forceps
B - Laparoscopic punch biopsy forceps
Cup forceps will tear whereas punch forceps will cut
This is a self-ligating loop (SurgiTie)
- A - preformed loop
- B - Knot
- C - Nylon carrier
- D - Scored black band
- E - Proximal end
- F - Optional delivery system for endoscopic surgery
How do pre-sx biopsies compare with post-excision histology in soft tissue sarcomas?
~60% are in agreement
~30% underestimate the grade
12% overestimate the grade
Agreement increased to 87% when classified as low vs high
What are the three options for obtaining lymph node biopsies
Excisional
Guillotine (if full excision risks potential vascular damage)
Laparoscopically with cup forceps
needle-core, punch, and incisional biopsies for STS
Needle-core biopsy techniques may be used to biopsy cutaneous and subcutaneous masses in dogs with accuracy comparable to that of surgical excision histopathology in 96% of cases.
How did sentinel LN mapping alter treatment in dogs with MCT
Altered the treatment plan of 42% of dogs
What is the main concern regarding thyroid biopsies?
Highly vascular - ultrasound guidance necessary, if freely movable consider excisional biopsy
Can you use automated TruCut biopsy deviced in cats?
with CAUTION!!
One study showed mortality 20% due to intense vagotonia - this was also seen at a similar rate with semiautomated devices however there were no deaths in this group
How to hepatic needle core biopsies compare with wedge/guillotime biospies?
Only 48% agreement between needle-core and wedge
83.3% needle-cor biopsies are diagnostic quality compared to 100% guillotine
How many samples are recommended when taking endoscopic biospies of the GIT?
6-8 gastric
10-15 small intestinal
3-5 large intestinal
This will only sample a portion of the mucosa!
What is the rate of final diagnosis with surgical GIT biopsies?
94%
Excisional biopsy
provides a large amount of information, (type, grade, and invasion) i
> not allow for preop planning compared to other biopsy techniques.
highly likely to lead to:
incomplete excision,
local recurrence
need for additional local treatment (more surgery or radiation)
List indications and contraindications to renal biopsy?
Indications
- glomerular disease
- Acute, unresponsive renal failure
Contraindications
- bleeding disorders
- severe anaemia
- uncontrolled hypertension
- pyonephrosis or abscess
- hydronephrosis
performed with ultrasound guidance, laparoscopy, or open surgery.
GIT biopsy
Hypoalbuminemia has been found to be a risk factor
Enterotomy defects may be closed routinely or closed in a transverse fashion to avoid luminal compromise.
Laparoscopic-assisted gastrointestinal biopsies
punch biopsy forceps to obtain samples of the gastrointestinal tract.
renal biopsy
What tissue?
options for obtaining
Cortical tissue only.
Sampling of the medulla significantly increases the risk of haemorrhage as well as infarction and fibrosis
Needle-core biospy (14g and vacuum-assisted obtain larger samples)
Surgical wedge biopsy - often required tempory vascular occlusion
List the risks associated with a renal biops
Haemorrhage (10% dogs, 15% cats)
AV fistula
Cyst formation
Infarction
Thrombosis
Infection
Fibrosis
Rarely hydronephrosis and death
Where is the ideal location for a pancreatic biopsy? Why?
Right distal limb
Far away from pancreatic ducts and duodenal vasculature
What is the rate of diagnostic sampling of CT-guided biopsy and FNA for thoracic masses?
Associated complications?
Diagnostic samples in
83% of biopsies
65% FNAs.
Complications rates were 43% (oneumothorax, haemorrhage) however none of these were clinical and no treatment was required
What are the options for obtaining a lung biopsy?
Suture ligation
Stapler
bipolar devise (Ligasure - only if <3cm from the edge)
What are the 2 needle options for a bone biopsy?
complications? cytology?
Jamshidi needle
Michele trephine (increased risk of pathological fractures due to size)
complications: non-diagnostic sample + fracture
cytology: similar accuracy results to histology for neoplasia ~80% and type of tumor as ~50%. In no case was a benign lesion diagnosed as malignant on cytology.
make sure remove biopsy tract in limb-spare sx
How should biopsy tissues be processed?
asap o prevent autoloysis
10% neutral buffered formalin in a 1:10 sample:formalin ratio
Eyes should be place in Bouin’s solution
inking or suturing for margin evaluation and preservation,
How can second opinion histopathology effect the results?
Partially changes the diagnosis in 20-29% (grade, tumour subtye or margin evaluation)
Completely changes the diagnosis in 10-19% (cell of origin or degree of malignancy)
Reductions in margin length after excision of grade II mast cell
tumors and grade I and II soft tissue sarcomas in dogs*
Milovancev 2018
In conclusion, surgical margins from grade II MCT and
grade I-II STS can be expected to reduce in length by a
median of 8.8 and 5.0 mm
respectively. These reductions occur at specific points along
the processing steps from surgical excision to histopathology
slide evaluation, with differences between MCT and STS.
The observed changes appear due to:
- physical factors (eg, tissue elasticity, myofibril contraction, and
histologic processing)
- biological factors associated with
microscopic tumor infiltration into grossly normal surrounding
tissues.
Biopsy of sentinel lymph nodes after injection of methylene
blue and lymphoscintigraphic guidance in 30 dogs with mast cell tumors
Ferrari 2020
Clinical prospective cohort study. Thirty client-owned dogs
Sentinel lymph nodes did not correspond to expected RLN in 19 of 30 (63%) tumors.
Histological examination confirmed an early or overt metastasis in 32 of 57 (56% SLN extirpated.
Conclusion: Sentinel lymph node mapping and biopsy with radionuclide and injection of methylene blue was associated with low morbidity and allowed detection of SLN in dogs with MCT at first presentation without scar tissue.
Assessment of the clinical
usefulness of ultrasound-guided
cytological specimens obtained from
gastrointestinal lesions in dogs and cats
Turner 2021
retrospective
Thirty (30/44) of the submitted cytological samples were considered clinically useful
Ultrasound-guided fine-needle cytological biopsies of gastrointestinal masses provided a clinically useful sample in two-third of the cases
Laparoscopic twist technique has the best overall artifact profile when comparing three laparoscopic
hepatic cup biopsy techniques for dogs
Buote 2022
Cadavers of 20 client-owned dogs
pulling the forceps forcefully caudally (the PULL technique),
rotating the forceps 360° (the TWST technique)
forceps through a 5-mm cannula (the CAN technique);
wedge biopsy samples served as the control (CON).
TWST technique resulted in the largest sample and had the fewest artifacts
