Principles Of Oncologic Surgery

Question 1

T/F: Malignant tumors in young dogs tend to be more biologically aggressive

Answer 1

T

Question 2

T/F: Breed and sex are prognostic

Answer 2

F

Question 3

What should you assess in your general physical exam of a cancer patient?

Answer 3

If there is a primary tumor then you should assess location and mobility (dermis v SQ). Palpate the regional lymph nodes and assess any other tumors

Question 4

What are 4 methods you can used to dx a tumor?

Answer 4

1. Fine needle aspiration
2. Needle core biopsy
3. Incisional biopsy
4. Excisional biopsy

Question 5

Briefly explain FNAs

Answer 5

FNA’s can categorize samples into epithelial, Mesenchymal, or round cells. They can be diagnostic for some types of tumors such as MCT’s. They’re a good first step because they’re economical, don’t require sedation and rule out non-neoplastic diseases. However, 13-35% of samples are non-diagnostic.

Question 6

Which types of tumor would you not want to FNA?

Answer 6

TCC or adrenal mass

Question 7

Does an FNA provide tumor grade?

Answer 7

NO

Question 8

Biopsy provides ___. What are the 3 types?

Answer 8

Tumor grade

• needle core biopsy
• incisional
• excisional

Question 9

Briefly explain needle core biopsy

Answer 9

Needle core biopsy often only requires sedation and local anesthesia but it only takes small samples that may not be diagnostic/representative

Question 10

Briefly explain incisional biopsy

Answer 10

These are typically wedge or punch biopsies that are good for soft, friable or inflamed tissues. They can be performed with sedation (oral), local anesthesia or general anesthesia. The biopsy scar needs to be able to be respected with the tumor

Question 11

T/F: you should do an incisional biopsy of an oral mass through the overlying lip

Answer 11

F, it would necessitate a more aggressive surgical resection, or RT after surgery, or rend the tumor resection unreasonable

Question 12

Briefly explain excisional biopsy

Answer 12

Excisional biopsies involves resecting the entire gross mass without definitive margins, this is common but controversial. It is usually diagnostic but not therapeutic

Question 13

What would be preferable over excisional biopsy?

Answer 13

To get the best results, you should do an FNA or needle core biopsy so you know what you’re working with. Then you can plan a definitive surgical procedure that gives the pet a better MST.

Question 14

If you do an excisional biopsy then __ take the fascial plane and only consider limbs with sufficient soft tissue coverage, NOT __

Answer 14

DO NOT, distal limbs

Question 15

What formalin ratio should should you use for biopsy?

Answer 15

10% buffered solution, 1 part tissue to 10 parts formalin

Question 16

How would you clinically stage a tumor you believe may be malignant?

Answer 16

1. Describe the extent of local tumor
2. Assess for the presence of local or distal at tumor metastases (rads, UA, CT, MRI, Nuclear Scintigraphy, CT)
3. Lymph node staging (enlargement, fixation, symmetry)

Question 17

What percent of dogs with oral melanoma had normal sized LN but had Mets

Answer 17

40%

Question 18

What type of margin is recommended for most solid tumors?

Answer 18

Radical or wide

Question 19

Radical resection

Answer 19

Removal of a body part

Question 20

Wide resection

Answer 20

Lateral and deep surgical margins to remove the complete tumor burden -> the precise amount of tissue depends on the tumor type and histopathological grade

Question 21

In wide resection you should take a minimum of __ fascial plane or __ for feline injection site sarcomas

Answer 21

1, 2

Question 22

Marginal resection

Answer 22

Incomplete excision of a tumor with residual microscopic disease that may need to be followed with alternative treatments such as radiation therapy

This is very likely for limb tumors such as MCT’s or STs

Question 23

If you have incomplete margins, what are the 4 treatment options?

Answer 23

1. No treatment
2. Staging resection of the surgical wound
3. Wide resection of the surgical wound
4. Adjuvant tx

Question 24

Debulking/intralesional surgery

Answer 24

Just don’t do this, you’re just leaving behind disease

Question 25

General cancer surgery principles

Answer 25

1. Avoid directly grasping the tumor with instruments as this leads to tissue fragmentation and exfoliation of tumor cells
2. Avoid penetrating tumor capsule
3. Avoid drains
4. Avoid flaps without confirmation of complete margins
5. Avoid contamination/tumor seeding

Question 26

What are some general cancer surgery principles?

Answer 26

1. Primary wound closure is preferred
2. Manage as open wound until confirm clean margins, then reconstruct
3. Healing by second intention
4. Always submit resected tumors for histology, NOT OPTIONAL
5. Submit the entire resected mass

Question 27

What information should Histopathology provide you?

Answer 27

It should give you the tumor type, grade and margins. This provides important information for risk of local recurrence and Mets, necessity of further treatment and prognosis