Equine Sarcoid & Melanoma Flashcards Preview

RUSVM Large Animal Surgery > Equine Sarcoid & Melanoma > Flashcards

Flashcards in Equine Sarcoid & Melanoma Deck (24)
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1
Q

__________ is the most common tumor in the horse

A

Sarcoid

Comprises 20% of all equine tumors (90% of all skin tumors)

2
Q

What is the etiology of equine sarcoid?

A

Papova virus

Related to bovine papilloma virus​

3
Q

What is the sex predilection for equine sarcoid?

A

No sex predilection

4
Q

Equine sarcoid can occur anywhere on the body, but where does it occur most commonly?

A

Limbs

  • 45% of sarcoid cases
  • Hindlimbs > forelimbs
  • Above tarsus/carpus > below tarsus/carpus
5
Q

What are the four forms of equine sarcoid?

A

Verrucous, Fibroblastic, Mixed, Occult​

6
Q

What form of sarcoid is shown here?

A

Verrucous sarcoid​

7
Q

What form of sarcoid is shown here?

A

Fibroblastic sarcoid​

8
Q

T/F: Benign neglect may be a therapeutic option for equine sarcoid

A

True

Considered for small tumors that are not causing discomfort, or impeding use

9
Q

T/F: Surgical excision is considered the most effective therapeutic option for equine sarcoid

A

False

No single approach to therapy has proved universally successful

10
Q

T/F: Most sarcoid lesions that are surgically excised recur within three years

A

True

Most recur within 6 months

11
Q

What cryogens are used for cryosurgery to remove equine sarcoid?

A

Liquid nitrogen, nitrous oxide, Freon​

12
Q

What is the average healing time for equine sarcoid after cryotherapy?

A

2.4 months​

13
Q

T/F: Most cases of equine sarcoid recur after cryotherapy

A

False

70% of cases are reported free of recurrence

14
Q

Concerning sarcoids, which statement is most accurate?

  • The rate of recurrence is less than 10% following resection
  • Immunotherapy is the treatment of the choice
  • They occur most commonly in the flank area
  • They are locally invasive, do not metastasize, and recur commonly
  • They commonly become fibrosarcomas following cryotherapy
A

They are locally invasive, do not metastasize, and recur commonly​

15
Q

T/F: Sarcoids are nonmetastatic skin tumors

A

True

16
Q

T/F: The four categories of sarcoids are based on the gross appearance. Sarcoids are the most common skin tumor of the equid.

A

True​

17
Q

Brachytherapy (CCDP) for treatment of equine sarcoid involves injection of what anti-neoplastic agent into the tumor?

A

Cisplatin

  • Treatment usually includes a series of 4 intratumoral injections of cisplatin given at 2 week intervals. The overall cure rate is 93%
  • MOA: Inhibition of DNA synthesis
18
Q

Xxterra® is a caustic agent used as immunotherapeutic treatment of equine sarcoid.

In a general sense, what does it do?

A

Changes the antigenicity of the sarcoid

  • The body recognized the cells as foreign and produces antibodies
  • Apply Xxterra® to the sarcoid and place a bandage over it for 4 days
19
Q

How do you definitively diagnose equine sarcoid?

A

Histopathology​

20
Q

It is difficult to differentiate between benign and malignant melanoma in horses. In aged gray horses, melanoma is more likely to present:

A

Benign​

21
Q

It is difficult to differentiate between benign and malignant melanoma in horses. In non- gray horses, melanoma is more likely to present:

A

Malignant​

22
Q

Melanoma lesions may be solitary or multiple. Where do they most commonly occur?

A

Perineum or ventral surface of the tail

23
Q

What H-2 receptor antagonist has been proposed for treatment of melanomas in horses?

A

Cimetidine

24
Q

T/F: Light-skinned cattle are more commonly affected with melanoma than dark-skinned cattle

A

False

Dark-skinned cattle are more commonly affected