surgical resection of tumors

Question 1

what is involved in grading and staging tumors?

Answer 1

• histological degree of malignancy
• metastatic spread
• paraneoplastic syndrome

Question 2

what is prohpylactic surgery?

Answer 2

preventative surgery,
eg Ovariectomy / ovariohysterectomy and mammary neoplasia

Question 3

what is definitive excision relating to oncological surgery?

Answer 3

removing the whole tumor

Question 4

what is palliative surgery?

Answer 4

removign part of the tumor to relive symptoms and externd life until euthanasia is needed

Question 5

what is cytoreduction?

Answer 5

removing as much tumor as possible knowing that some will be left behind
utilising adjuvant therapy eg chemotherapy or radiotherapy

Question 6

what is an example of management of oncological emergency

Answer 6

surgery to treat a bleeding splenic tumor - won’t know if tumor is malignant or begnin but just dealing with the hypovolemic animal

Question 7

what are the stats relatated to mammary neoplasia and ovariohystorectomy?

Answer 7

neutering reduces the risk of mammary neoplasia to an incidence of 0.5% if neutered before the 1st estrous,

8% before the 2nd estrous,

26% after 2 ovarian cycles,

and no protective effect after 2.5 years

Question 8

why is tumor type and grade needed before surgery?

Answer 8

direct surgeon towards recomended surgical margins

Question 9

how can we grade tumors?

Answer 9

cytology:
FNA and impression smear

histology:
- core biopsy
- punch biopsy
- incisional biopsy
- excisional biopsy (remove the tumor and then submit for histopathology) (rare)

Question 10

what is the issue of usign cytology to try and grade a tumor?

Answer 10

will tell you name of tomour but are not supplying enough cells to be able to grade the tumor

Question 11

what is staging of a tumor?

Answer 11

looking for metastatic disease (spead) using imaging

Question 12

what are the 4 methods of tumor surgery?

Answer 12

• debulking/intralesional/cytoreduction (will leave some cancer cells)
• marginal reesection
• wide resection
• radical resection

Question 13

lable this tumor

Answer 13

P = pseudocapsule descrete capsule seen most oftern with sarcomas (less likeing in carinomas
R = reactive zone (inflammation, can contain cancer cells)
T = tumour
sk = skip metastases (variable occurance, depends on type of cancer)
st = satellite metastases (variable occurance, depends on type of cancer)

Question 15

what is the pseudocapsule?

Answer 15

compressed cancer cells and surrounding fascial layers that give tumor the appearance it has a descrete capsule, but is not a barrier to cancer spread, it can contain neoplastic cells

Question 16

define Debulking/intralesional/cytoreductive excision

Answer 16

leaves macroscopic volumes of tumour. Will recur unless given adjuvant therapy (which is less effective if gross vs microscopic tumour remains)

Question 17

define marginal surgery:

Answer 17

excision immediately outside the pseudocapsule of the tumour, leaving behind microscopic volumes of tumour. Local recurrence likely without adjuvant therapy
(Pseudocapsule of tumour = compressed tumour cells rather than connective tissue, not a barrier and therefore cancer cells can migrate to surrounding tissue)

tumour removal with minimal amount of surrounding normal tissue

Question 18

what is the other name for marginal excision?

Answer 18

local excision

Question 20

define wide excision

Answer 20

removal of the tumour with complete margins of normal tissue in all directions.
Local recurrence unlikely

Question 22

define radical (or compartmental) excision:

Answer 22

removal of an entire anatomical structure or compartment containing the tumour; e.g., limb amputation for a primary bone tumour, or mastectomy
- Local recurrence unlikely
- Often applies for sarcomas (which can extend
along fascial planes rather than through them)

need to know staging as don’t want to put animal through this if there is chance that tumor could have metastasised

Question 23

what is the highest surgical does for treating tumors?

Answer 23

radical excision

Question 24

when considering wide excision what do you need to consider?

Answer 24

what the natural barriers are to cancer cell spread and therefor remove everything up to these barriers:

lateral margins are easier to calculate but deep margins are harder

The most effective natural barriers to the spread of cancer are collagen-rich relatively avascular tissues, including fascia, ligaments, tendons and cartilage

Fat, subcutaneous tissue, muscle and other parenchymatous organs offer relatively little resistance to invading tumour cells