Surgical Oncology Flashcards
what is surgical oncology
patient centered approach to tumor management
what are three limitations to consider with surgical oncology
- physical exam
- knowledge of tumor biology and disease process
- effectiveness and limits of surgical techniques
what are two goals to know with surgical oncology
- many patients will be at advanced stages
- palliation vs cure (make sure O is on the same page)
what is staging
- extent of disease
- determined by pre-operative evaluation (nodes, lungs, etc.)
what is grading of disease
- tumor behaviour
- requires histopathology
- associated with propensity to spread elsewhere vs local aggressiveness
what are the 4 questions for surgical oncology
1) what is it
2) where is it
3) how bad is it
4) what to do about it
what are two techniques we can use to determine what cancer we are working with
cytology and histopathology
what is the difference between cytology and histopathology
cytology:
- FNA
- examines individual cells
histopathology:
- biopsy
- examines tissue sections
T/F cytology can help determine whether cancer or not cancer
T
what are the 3 main types of cancer
- round cell tumor
- sarcoma
- carcinoma
what is the biggest thing to try to minimize when performing an FNA
hemorrhage
what size needle and what size syringe should you use for an FNA
22 or 25g
3 or 6cc
when doing an FNA, how far should you pass the needle through the mass
2/3 of the thickness
why should we avoid the center of the mass when doing an FNA
likely necrotic so hard to get an answer from there
why is it recommended to make many slides when doing an FNA
- area of necrosis
- potential to miss the lesion
- dx in the adjacent area
T/F when performing an FNA you should typically be able to see gross material in the syringe, and if you don’t you likely did not collect anything
F; if you see something, it is probably hemorrhage (not good)
all cutaneous and subcutaneous masses should be ______________ and a ________ should be done
aspirated; body map
what are the 6 round cell tumors
- TVT
- melanoma
- mast cell tumor
- lymphoma
- plasma cell tumor
- histiocytoma
round cell tumors usually exfoliate (poorly/well)
well
T/F you can usually get a specific Dx for round cell tumors off of cytology alone
T
carcinomas usually exfoliate (poorly/well)
well
with cytology, what can we tell about carcinomas
if they are malignant or benign; sometimes specific cell type
sarcomas usually exfoliate (poorly/well)
poorly
what type of tumors typically never exfoliate in effusions
sarcoma
do we usually get a lot of info from cytology of a sarcoma
not really… it does not exfoliate well, the exact type usually requires histology and it can be a really difficult cytologic diagnosis
what are two pros of biopsy
- better planning for Sx
- getting a definitive Dx enables pre-op radiation
what are two cons of biopsy
- two procedures (cost, progression while waiting for Sx)
- risk of local recurrence (unless you remove entire biopsy tract during Sx)
what are some indications to perform a biopsy
1) you cannot get a good answer from cytology alone (ex. sarcoma)
2) if the grade of tumor would affect the treatment elected
when would biopsy be contraindicated
1) if you can get an answer off of cytology alone
2) if surgery approach would not be affected by histopathology
3) if you are unsure of surgical approach and biopsy may compromise the curative intent procedure
what are the 2 types of biopsy
incisional and excisional
what is really key with an excisional biopsy
to leave the fascial plane intact
in general, the margins for excisional biopsy are
<1 cm
what are two benefits and a limitation of incisional biopsy
advantages:
1) not changing definitive surgical margins
2) should not change the chances of a clean cut
limitation:
1) always requires a second surgery (including benign)
what is a benefit and two drawbacks of excisional biopsies
benefit
1) potentially curative for benign disease
drawbacks
1) increases margins if malignant
2) decreased chances of clean cut
biopsy should never be performed without first doing what
cytology
___________ biopsy should be performed over ___________ biopsy except for in what 2 cases
incisional; excisional
1) location means you cannot get a larger margin regardless of Sx
2) very small cutaneous masses <1cm
what are two methods for incisional and two methods for excisional biopsy
incisional:
- wedge/Keyes punch
- core/tru-cut needle biopsy
excisional:
- surgical excision
- Keyes punch
where should you take a biopsy with a wedge or Keyes punch
center, not periphery
you should close a wedge/punch biopsy with what type of suture
non-absorbable (ex. prolene)
T/F Keyes punch can be used for incisional and excisional biopsy
T
a Keyes punch generally requires ___________ whereas a Tru-cut biopsy can be done with _____________
anesthesia; sedation
when would it not be good to do a Tru-cut or core biopsy? when does it work really well?
very small mass; works well when you have a very deep mass
T/F properly performed biopsies may increase the likelihood of future metastasis or decrease the likelihood of future control
F
what does staging account for
1) local disease (T)
2) local metastasis (N)
3) distant metastasis (M)
staging =
extent of disease
how can staging help define the extent of disease
- aids in planning treatment
- allows more accurate prognostication
- assists in evaluation of patient response to therapy
T/F bloodwork will generally be normal in a patient with early stage cancer (the exception being liver tumors)
T
what are 3 ways to assess distant metastasis
1) thoracic radiographs
2) abdominal ultrasound
3) bone marrow
how do we evaluate local metastasis
by evaluating lymph nodes
1) identify the draining node
2) cytology
3) histopathology
what is a limitation of radiographs for assessing thoracic metastases and how can we get around this?
won’t catch mets <7mm in size; use CT (more sensitive)
if you are going to take RADS, what is absolutely critical
3 views!
prognosis is based on (3)
tumor type, grade and stage
why do we consider prognosis both pre and post op
1) may impact surgical approach pre-op
2) may change based on histopathology results post-op
current cancer therapies in SA include (4)
- surgery
- radiation
- chemotherapy
- investigational
what are the 2 local treatment modalities for cancer
- surgery
- radiation (local)
what are the 3 systemic treatment modalities for cancer
- radiation
- chemotherapy
- immunotherapy
what should you consider when planning positioning of the animal for excision sx
- tension lines
- motion areas
what are 4 surgical considerations when doing an excision sx
1) minimize tumor handling
2) ligate venous side first
3) change gloves and instruments often
4) lavage
what happens to tissues following excision, and what effect does this have
- retract
- makes defect appear larger
what is the pseudocapsule
layer of compressed neoplastic cells encapsulating the tumor
what is the reactive zone
reactive host cells surrounding the tumor (outside the pseudocapsule)
what is a satellite tumor
neoplastic cells outside the pseudocapsule
what is a skip metastasis
neoplastic cell distant to the tumor in the same compartment (rare)
what are the two types of non-curative surgical excisions
intracapsular and marginal
what are the two types of curative surgical excisions
wide and radical
you should only ever do intracapsular surgery for ______ tumors
benign
what are the margins for intracapsular surgery
there are no margins
what are the margins for marginal surgery
minimal
marginal surgery leaves _________ disease behind whereas intracapsular surgery leaves ________ disease behind
microscopic; gross
what would be two instances where you might elect for marginal surgery
location does not allow wide margins; benign tumor
T/F wide surgery addresses skip mets
F
what are three types of cancers where we would elect for wide surgery
sarcomas, mast cell tumors, GI tumors
margins need to consider both ______ and ___________
deep and lateral
what are typical margins
1-3cm depending on the tumor type
how do you do wide surgery
skin incision, then extend deep and evenly until you reach the fascial plane
what makes up the deep margin for a wide surgery
the fascial plane
what is the most common reason for a dirty margin
lack of fascial plane
T/F if the tumor is stuck to the fascial plane it is no longer a barrier
T
what are the fascial planes (4)
fascia, bone, tendon/ligament, muscle
what area tends to have limited fascial planes
distal limbs
T/F the cutaneous trunci is uniform in dogs
F
why is elliptical incisions not recommended
- extends cancer field
- not great for malignant lesions
why do we want to avoid a seroma or hematoma for a patient with cancer
it can disperse residual tumor cells
why is it not recommended to put in a drain for a cancer sx
increases the cancer field if you had to recut
what are examples of radical surgery
amputation, splenectomy, lung lobectomy
you should submit tumor samples in formalin in what radio
10:1, depending on size
you should ink what
lateral and deep margins
it is best to ink your deep margin where
directly below the tumor (not the whole surface because bleeding can occur)
what is the benefits of submitting your tumors to a pathologist
- grade
- margins
- diagnosis and certainty
T/F histologically clean margin = clinically clean margin
F: may be a clean margin according to the pathologist but does not indicate that you took a fascial plane
in any situation with a dirty margin, it is a good idea to consider
referral
T/F it is best to have a diagnosis prior to surgical intervention
T
