E1: Sx Oncology

Question 1

What is a pre-treatment biopsy? When is it performed? What are the 5 indications? What are the types?

Answer 1

Incisional biopsy

Before definitive treatment to get more info about tumor

1. When FNA has provided insufficient info for surgical planning
2. If type of treatment is dependent on tumor type
3. If it alters the owners willingness to treat
4. Tumor in difficult anatomic location
5. Treatment has a high morbidity

Needle core, Wedge and Punch

Question 2

What is a post-treatment biopsy? When is it performed?

Answer 2

Excisional biopsy

After surgical removal of tumor to get more complete picutre, evaluate margins

Rarely the first option for getting tissue diagnosis

Question 3

What type of biopsy would be indicated for a cat that has a firm hypodermal mass? Why?

Answer 3

Incisional biopsy

Because it could be an injection site FSA and would require really aggressive surgery

Question 4

An incisional biopsy increases the risk of local recurrence. How do you diminish/eliminate this risk?

Answer 4

Remove entire biopsy tract during second surgery

Question 5

Why is the orientation of incision an important consideration when performing an incisional biopsy?

Answer 5

Must orient along tension lines (longitudinally) and in a direction that won’t increase the surgical field for the second surgery

Question 6

What size punch biopsy is needed to procure a diagnostic sample? For what types of masses is this biopsy counter-indicated?

Answer 6

>6mm

Do not use for hypodermal masses

Question 7

What type of biopsy is indicated for ulcerated or necrotic tissues that are deeply located? What instrument do you use to maintain tissue retraction for deeper lying tumors?

Answer 7

Wedge biopsy

Gelpi retractors

Question 8

What type of biopsy is indicated for a testicular mass?

Answer 8

Excisional

Question 9

What type of biopsy is indicated for a lateral thoracic undiagnosed 1cmx1cm dermal mass on a large breed dog?

Answer 9

Excisional

Question 10

Why is placing a drain counter-indicated post-excisional biopsy?

Answer 10

Increases risk of tumor seeding

Question 11

What is the Enneking System? What are the main designations?

Answer 11

Classification of surgical dosing

Intralesional (least invasive) vs Marginal vs Wide vs Radical (most invasive)

Intralesional/capsular= part of tumor and part of capsule

Marginal= part of capsule

Wide and radical= grossly normal tissue cut only

Question 12

When would you make an intracapsular dissection?

Answer 12

Lipoma excision

Question 13

When is a marginal excision indicated? What margins are indicated for different tumor types?

Answer 13

Lateral margins <1cm for carcinoma

<2cm for MCT

<3cm for soft tissue or bone sarcoma

<5cm for feline injectionsite sarcoma

Question 14

What type of exicsion is indicated for perianal region tumors?

Answer 14

Marginal

Question 15

What are, generally, the margins you need to take for a MCT? What if you know it is a Grade I? Grade II? Grade III?

Answer 15

3cm lateral and 1 facial plane deep OR use the widest diameter of tumor as the lateral margin

_Grade 1: 1_cm

_Grade II: 2_cm=90% clean, 3cm=100% clean (most common MCT grade)

_Grade III: 3_cm

Question 16

Generally, what margins should you take for benign tumors?

Answer 16

1cm lateral and 1cm deep

Question 17

Generally, what margins should you take for a sarcoma?

Answer 17

3cm lateral

1 facial plane or 2 muscle planes deep

Question 18

Generally, what margins should you take for a oral tumors?

Answer 18

Acanthomatous ameleoblastoma = 1cm + BONE

Malignancies = 1cm laterally + bone deep

Question 19

What margins of a biopsy should you ink? What colors are best?

Answer 19

All cut surfaces (NOT the skin)

Yellow or Black

Question 20

What is indicated prior to fixation for a large specimen?

Answer 20

Bread-loafing

Question 21

What is a “narrow excision”?

Answer 21

Clean but close

2-5mm of normal tissue between tumor and cut edge

Question 22

What is the R classification for margin assessment?

Answer 22

R0 = no residual tumor

R1= microscopic residual tumor

R2= macroscopic residual tumor