Lecture 10 2/19/25 Flashcards

1
Q

What does “a chance to cut is a chance to cure” refer to?

A

-surgery is the most important component of treatment for solid tumors in dogs and cats
-first attempt at removal is best chance at a cure

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2
Q

What are the aspects of client education surrounding surgical oncology?

A

-cancer diagnosis is difficult news for owner; consider counseling surrounding news/decisions
-provide owners with options/explain the potential outcomes of each option
-explain the expected goals of treatment, including cure/survival time, complications, cosmesis, and pain level

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3
Q

What are the characteristics of cancer staging?

A

-PE and history eval. can indicate co-morbidities; indicates health for anesthesia, surgery, and recovery
-standard staging protocol involves thoracic radiographs, abdominal ultrasound, and regional/distant lymph node evaluation
-advantaged imaging including nuclear scintigraphy, CT, and MRI can be used

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4
Q

What are the components of tumor anatomy?

A

-gross tumor
-pseudocapsule
-microscopic tumor

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5
Q

What are the characteristics of the pseudocapsule?

A

-fibrous tissue in reaction to growing mass
-limit of many benign tumors
-malignant tumors will continue to grow beyond this

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6
Q

What are the characteristics of microscopic tumor?

A

-satellite cells or tumor fingers/tendrils
-found in the reactive zone

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7
Q

Which tissue planes are resistant to tumor penetration?

A

-fascia
-joint capsule
-cartilage
-bone

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8
Q

What is FNA used to diagnose?

A

-mast cell tumor
-lymphoma vs reactive lymph node
-melanoma
-inflammation vs sarcoma

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9
Q

When is biopsy indicated?

A

when FNA results are:
-inconclusive
-non-diagnostic
-not fitting with clinical picture

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10
Q

What information can be provided by biopsy?

A

-benign or malignant
-grade of neoplasia
-median survival time
-response to surgical treatment
-need for radiation and/or chemo

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11
Q

What are the risks of biopsy?

A

-tumor metastasis to local tissues
-hemorrhage
-tissue rupture

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12
Q

What are the characteristics of tru-cut/needle biopsy?

A

-most commonly performed for tumors within body cavities
-require heavy sedation or anesthesia
-can be percutaneous and ultrasound guided, laparoscopic/thoracoscopic, or via laparotomy/thoracotomy

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13
Q

What are the steps to taking a tru-cut/needle biopsy?

A

-sterile skin prep
-blind or ultrasound guidance
-insert inner needle
-advance cutting sheath
-extract device
-remove sample from channel with a needle

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14
Q

What are the characteristics of incisional biopsy?

A

-sharp incision; wedge or punch biopsy
-removal of portion of tumor; majority still intact, but taking more than a needle biopsy
-heavy sedation w/ local anesthesia for dermal tumors; general anesthesia for body cavity and deep subcutaneous tumors
-used for large tumors in bad locations
-second procedure needed to remove full tumor
-location very important; do not want to go central, but must stay within confines of tumor tissue; poorly planned biopsy leads to larger margin for later removal

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15
Q

What are the modifications made for large and/or deep tumors with regards to incisional biopsy?

A

-large tumors may require multiple biopsy sites to ensure appropriate diagnosis
-deep tumors require an approach to the mass that involves incisions and dissecting down to the tumor

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16
Q

What are the characteristics of excisional biopsy?

A

-sharp incision around the periphery of the tumor
-removal of all gross disease and small barrier of normal tissue; pseudocapsule is removed but satellite tumor cells may remain
-heavy sedation and local anesthesia for small tumors; GA for large tumors and tumors around head/ears

17
Q

What are the pros and cons of excisional biopsy?

A

pros:
-can be curative for benign tumors with only one procedure
-provides best chance for cure since it is the first cut

cons:
-may increase margin necessary for malignant tumors
-may have higher grade, rapid tumor regrowth

18
Q

What are the characteristics of bone biopsy?

A

-done on suspicious bone lesions
-typically require small surgical approach under GA
-can use jamshidi needle or michele trephine; based on bone size

19
Q

What are the characteristics of surgical intent?

A

-outcome the oncology team wishes to achieve
-based on tumor type, tumor stage, advanced imaging, and tumor location

20
Q

In which instances might a tumor-free surgical margin not be attempted?

A

-would not benefit quality of life
-disfiguring or non-cosmetic
-no advantage for treatment
-not compatible with life

21
Q

What are the characteristics of curative intent surgery?

A

-goal is to achieve tumor-free margin and cure patient
-cannot be done if metastatic disease present
-big procedure requiring GA, removal of lots of tissue, and potentially amputation
-may require major reconstruction
-must have a plan in the event of a “dirty” margin

22
Q

What are the characteristics of palliative intent surgery?

A

-goal is to improve quality of life through improved function and/or pain relief
-done when curative intent is not possible
-may prolong good QOL and delay euthanasia

23
Q

What are the characteristics of surgical dose?

A

-amount of surgical resection planned
-based on intent of surgery, invasiveness of tumor, and anatomy of the area

24
Q

When is wide or radical excision used?

A

curative intent surgery in which the goal is to remove both gross and microscopic disease

25
What is radical excision?
-removal of a body "compartment" -can include removal of entire organ or limb
26
What is wide excision?
removal of a large amount of predetermined normal tissue around tumor; multiple cm of healthy tissue margin
27
What are the characteristics of marginal excision?
-planned excisional biopsy -included removal of gross disease and pseudocapsule -performed to avoid curative intent surgery, such as due to cosmesis, owner decision, or presence of metastasis -may require adjuvant therapy such as radiation or chemo
28
What are the characteristics of cytoreduction/debulking?
-residual gross disease is left behind; can undergo rapid regrowth -gross disease left behind is not typically responsive to radiation and chemo -generally not recommended; not effective and leads to complications with hemorrhage and dehiscence
29
What are the characteristics of lymph nodes?
-FNA of local lymph nodes is recommended for nearly all externally palpable tumors -surgical excision can be done with confirmation of metastasis -often removed during limb amputations and separated out for path. eval.
30
What are the general surgical concepts when performing surgical oncology?
-excise ALL previous biopsy tracts; assume presence of tumor within them -early vascular ligation can minimize distant metastasis -try not to directly handle tumor; considered DIRTY -change gloves and instruments between tumor removal and closure -use absorbable monofilament suture -insert hemoclips if considering radiation -primary closure is preferred over reconstructive techniques -avoid drains
31
What is to be expected during post-op care?
-mast cell tumors can take longer than 10-14 days to heal due to inflammatory mediators -seromas may occur, especially with amputations and wide exicisons -seromas should be treated with warm packing and compression bandages -seromas should NOT be drained unless patient is uncomfortable or infection -dehiscence can occur due to tension on closure or excessive activity -necrosis at tips of skin flaps is common
32
What are the characteristics of path. submission?
-anything important enough to remove should be submitted -mark margins in different colors of ink (NOT red) prior to placing in formalin -provide thorough history and surgical report
33
What are the characteristics of mast cell tumors?
-most common skin tumor in dogs and one of the most common in cats -boston terriers, boxers, and pugs at increased risk -surgery is treatment of choice -curative intent surgery is wide excision -want 2 cm lateral to tumor and 1 fascial plane deep for margins -recurrence at dirty margin is only 30%
34
What are the characteristics of soft tissue sarcoma?
-slow growing and locally invasive -clean margins are most important prognostic indicator for local disease -recurrence is grade dependent -curative intent surgery is wide excision -want 2-3 cm lateral to tumor and 1 fascial plane deep for margins -radical excision needed for recurrent or high grade tumors
35
What are the characteristics of injection site sarcomas in cats?
-associated with trauma and inflammation -seen with vaccines, long acting medication injections, and non-absorbable sutures -more commonly high grade -aggressive local behavior, but metastasis in less than 25% -most effective therapy is surgery -want 5 cm lateral to tumor and 2 fascial planes deep for margins
36
When should surgery be considered in cats for suspected injection site sarcoma?
-masses at injection sites for 3+ months -masses that grow in size over 4 weeks -masses greater than 2 cm in diameter
37
What is the follow up for cats with injection site sarcoma?
-radiation therapy -monitor frequently for metastasis
38
What are the characteristics of malignant melanoma?
-dermal melanoma can be benign or malignant -oral melanoma is malignant and is the most common malignant oral tumor -malignant melanoma should have curative intent surgery -malignant melanoma requires 2+ cm lateral margin, digit amputation, maxillectomy, or mandibulectomy depending on location -can use marginal excision for smaller, benign masses