Principles Of Surgical Oncology

Question 1

Incisional biopsy vs. Excisional biopsy… GO!

Answer 1

Incisional (“pre-treatment”):
Performed in order to obtain additional information about the tumor prior to definitive treatment

Excisional (“post-treatment”):
Process of obtaining histopathologic information following surgical removal of the tumor

Question 2

Which type of biopsy requires a 2nd procedure and is potentially more costly?

Answer 2

Incisional

Question 3

When should we go for pretreatment biopsy?

Answer 3

When FNA has provided insufficient information to allow us to continue adequate surgical planning
If type of treatment would be altered
If alters owner’s willingness to treat
Difficult anatomic location
Treatment has high morbidity

Question 4

What should the generic sample size be for incisional biopsies, that Dr. C mentioned in class?

Answer 4

1cm cubed

Question 5

What type of biopsy should we use for a relatively accessible mass?

Answer 5

Tru-cut! (14, 16, and 18 G needles)
Obtain multiple samples*

Question 6

What type of biopsy should we procure for small/dermal tumors?

Answer 6

Punch biopsy!
Always >6mm punch!!

*DO NOT use for hypodermal masses—>risk of hemorrhage*

Question 7

What type of biopsy should we procure for ulcerated or necrotic tumors, located deep SQ or intramuscularly?

Answer 7

Wedge! Ideally, obtain sample at junction of Ab/normal, but just tumor tissue is ok if concern for increasing field of contamination

Question 8

In using a wedge biopsy, what tool should we include for maintaining tissue retraction and reaching the tumor?

Answer 8

Gelpi retractors!

Question 9

When should we procure excisional biopsies?

Answer 9

When treatment would NOT be altered by tumor type or grade (i.e. testicular mass)

If the procedure to get to the mass is invasive (i.e. splenectomy) or carries high risk of hemorrhage

If the location is permissive of wide margins WITHOUT compromising the potential for future re-excision (if needed)

​lateral thorax/flank

Question 10

A large breed dog has an undiagnosed 1cm x 1cm dermal mass on his lateral thorax… what type of biopsy should we procure?

Answer 10

Excisional!

Question 11

3 general criteria/considerations for excisional biopsy… GO!

Answer 11

1. Small mass
2. Good location (i.e. flank/thorax)
3. Cytology, exam, and history support a benign diagnosis

Question 12

What is an intracapsular resection?

Answer 12

Cutting right thru the tumor, thru the capsule, thru the surrounding skin, and you’re basically “peeling” the tumor out... {curettage/debulking}
-least invasive!

*only for lipoma excision, really…*

Question 13

What is the lateral margin for marginal resection in treating carcinomas?

Answer 13

<1cm

Question 14

What is the lateral margin for marginal resection in treating soft tissue and bone sarcomas?

Answer 14

<3cm

Question 15

What is the lateral margin for marginal resection in treating mast cell tumors?

Answer 15

<2cm

Question 16

What is the lateral margin for marginal resection in treating feline injection-site sarcomas?

Answer 16

<5cm

Question 17

What type of biopsy might we choose to approach any malignant, solid tumor?

Answer 17

Wide excision

Question 18

What are the lateral margins for wide excision in treating carcinomas?

Answer 18

_>_1cm

Question 19

What are the lateral margins for wide excision in treating feline injection-site sarcomas?

Answer 19

_>_5cm

Question 20

What are the lateral margins for wide excision in treating mast cell tumors?

Answer 20

_>_2cm + A FASCIAL PLANE DEEP!

Question 21

What are the lateral margins for wide excision in treating soft tissue and bone sarcomas?

Answer 21

_>_3cm + a fascial plane deep!
(Or 2 muscle planes deep, if no fascia)

*soft tissue sarcomas are notorious for having tentacles that extend well beyond the soft tissue*

Question 22

How would we classify a splenectomy according to Enneking Classification?

Answer 22

Radical excision (removal of entire body compartment)

Question 23

What type of excision would we use to treat tumors on extremities, near important structures (eyes) or in perineal regions?

Answer 23

Marginal! (Most commonly)

Question 24

What margins should we use for acanthomatous ameloblastoma?

Answer 24

1cm {must get bone margin!}

Question 25

What margins do we want for malignant oral tumors? (Melanoma, SCC, Fibrosarcoma)

Answer 25

2cm laterally + a bone margin deep!

Question 26

What type of excision do we use to treat thyroid or anal sac tumors?

Answer 26

Marginal excisions!
Because they have predictable pseudocapsules, very compressed, and don’t tend to have tentacles; we can get by with marginal, as opposed to wide, lateral margins on these

Question 27

What’s the “gold standard” way of managing a MCT?

Answer 27

Wide excision:
2-3cm lateral margins
+ a fascial plane deep!

Question 28

Concerning biopsy submission logistics, what tissue thickness is ideally recommended for appropriate fixation?

Answer 28

0.5-1.0cm