Soft Tissue Sarcomas

What are the clinical characteristics of soft tissue sarcomas?

Middle aged to older pets

Arise from mesenchymal tissue (fat, muscle, bone)

Pseudoencapsulated

Locally invasive

What is the capsule made of with soft tissue sarcomas?

Tumors cells, makes marginal excision a failure

What is the biological behavior of soft tissue sarcomas?

Hematogenous metastasis in <20%

Rare LN mets

Grade-dependent progression

Where do soft tissue sarcomas typically metastasis to?

Lungs

What is the challenge with a FNA of soft tissue sarcomas?

They do not exfoliate well and 15% of them are misdiagnosed

How do you stage soft tissue sarcomas?

3-view thoracic rads (lungs is most common met site)

How do you grade soft tissue sarcomas?

Differentiation, mitoses, necrosis

What does a well differentiated tumor look like?

Similar to normal cells (better prognosis)

There are a lot of soft tissue sarcomas, but they all behave similarly which is how?

Slow growing masses but very locally invasive with low mets rates

Biggest problem is local control of the tumor

What soft tissue sarcomas behave differently?

Histiocytic sarcoma, synovial cell sarcoma, hemangiosarcoma, rhabdomyosarcoma, oral fibrosarcoma, PNST of brachial or lumbar plexi

How do you treat saft tissue sarcomas?

Multimodal with

• Surgery (never scoop)

• Radiation

Describe the surgery part of soft tissue sarcoma tx

Three cm margins and one facial plane deep

NEVER scoop tumor out of capsule need to remove whole thing at once amputation may be necessary for clean margins

What is the efficacy of radiation for soft tissue sarcomas?

If incomplete resection, 85% control with MST of 5 years

RT alone controls tumor but does not regress

What is the prognosis for soft tissue sarcomas?

Surgery alone >3 years

Surgery + RT > 6 years

What surgery gives us our best chance to remove a soft tissue sarcoma?

The first one

What are injection site sarcomas secondary to?

Chronic inflammation

What injections are associated with injection site sarcomas?

Vaccines, lufenuron, long-acting steroids, NSAIDs, vascular access ports, deep nonabsorbable sutures

T/F only adjuvant vaccines cause soft tissue sarcomas?

False, that was initial theory but has been proven wrong

A sarcoma in a cat is most likely what?

An injection site sarcoma

What is timeline of ISS (injection site sarcomas)?

4 weeks to 10 years

What plays a role in ISS (injection site sarcoma)?

Genetics, especially mutated p53

What is the behavior or ISS?

Aggressive, highly pleomorphic with necrosis, mitoses, and inflammation

60% or more are grade III

What are the common locations for ISS?

Interscapular, R pelvic limb and lateral abdomen, L pelvic limb and lateral abdomen but has changed over time as where people give injection to cats have changed

How do you dx an ISS?

Will be very aggressive on FNA and can lead to misdiagnosis

biopsy with a punch or wedge is good because removal of it all is still possible

CT or MRI is necessary for tumor extent

stage with 3 view thoracic rads

What do you need to do a workup of a suspected ISS to rule out a normal vaccine reaction?

Mass present >3 months after injection

Mass is >2 cm in diameter

Mass increases in size more than 1 month after injeciton

(3,2,1 rule)

What surgery do you want for a ISS?

2cm margins (only for use as a marginal resection or excisional biopsy to confirm dx) recurrence is common with just marginal resection

5cm and 2 fascial planes deep is best for prolonged recurrence

What is the efficacy of adjuvant radiation for a ISS?

RT helps with local control

30-45% will still recur

What is the efficacy of adjuvant chemo for a ISS?

Helps with local control and helps fight mets

Doxorubicin is best

What is the prognosis for a ISS?

Poor with surgery alone

Complete resection is key to improve survival

Best with multimodal therapy (sx, chemo, RT) has a 2 yr prognosis

What is the best way to help with ISS prognosis?

Use recommended vaccination sites and never give interscapular

Record what was given where

What is a HSA?

Hemangiosarcoma

What is the signalment for HSA (hemangiosarcoma)?

Middle aged to older dogs

What are the forms of HSA (hemangiosarcoma)?

Visceral and cutaneous

What gest visceral HSA?

GSD, golden, labs

What gets cutaneous HSA?

Dogs with minimal pigment and thin hair coats like italian greyhound and whippet

What is the most common splenic tumor?

HSA

What are the locations of a HSA?

Spleen most of the time

Also, right atrium, skin and subcutis, liver

Describe splenic tumor types

50% are benign, 50% malignant

50% of malignant are hemangiosarcomas

Splenic tumor + hemoabdomen is a 75% chance of a HSA

What is the behavior of HSA?

Very aggressive with 80% mets (except for dermal/cutaneous)

Up to 25% of goldens have right atrial and splenic involvement

What is the presentation for a visceral HSA?

Abdominal swelling

Acute weakness/collapse (white gums, hard breathing)

Sudden death (shock)

Can wax and wane (bleed, resorb, repeat)

What does a right atrial HSA look like?

Exercise intolerance, dyspnea, ascites

Pulsus paradoxis 

What does a cutaneous HSA look like?

Bleeding mass and ulcerated lesions

How do you work up a HSA?

Anemia with schistocytes, thrombocytopenia

DIC is possible risk

Thoracic and abdominal rads is vital prior to tx

When do you do a ECG with a HSA?

If globoid heart on xra

Suspect pericardial effusion

Golden retriever or mets

When do you not do a ECG with a HSA?

Lack of metastatic disease or pericardial effusion

What is the problem with finding RA masses?

Blood clots can look the same, effusion helps you rule out clots

When should you aspirate a HSA?

Splenic masses are usually unrewarding

Can be good for cutaneous or SQ lesions

How do you treat at suspected HSA on the spleen?

Splenectomy (stabilize first)

Biopsy anyway because it could be something else and the dog could have a much better prognosis

Chemo with doxorubicin is recommended (unless cutaneous)

What is a common development after HSA sx?

Ventricular arrhythmia

What is the prognosis for HSA?

Poor especially if mets prior to sx