Equine Sarcoid & Melanoma Flashcards Preview

RUSVM Large Animal Surgery > Equine Sarcoid & Melanoma > Flashcards

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

__________ is the most common tumor in the horse

Sarcoid

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

2

What is the etiology of equine sarcoid?

Papova virus

Related to bovine papilloma virus​

3

What is the sex predilection for equine sarcoid?

No sex predilection

4

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

Limbs

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

5

What are the four forms of equine sarcoid?

Verrucous, Fibroblastic, Mixed, Occult​

6

What form of sarcoid is shown here?

Q image thumb

Verrucous sarcoid​

7

What form of sarcoid is shown here?

Q image thumb

Fibroblastic sarcoid​

8

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

True

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

9

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

False

No single approach to therapy has proved universally successful

10

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

True

Most recur within 6 months

11

What cryogens are used for cryosurgery to remove equine sarcoid?

Liquid nitrogen, nitrous oxide, Freon​

12

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

2.4 months​

13

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

False

70% of cases are reported free of recurrence

14

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

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

15

T/F: Sarcoids are nonmetastatic skin tumors

True

16

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

True​

17

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

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

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

In a general sense, what does it do?

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

How do you definitively diagnose equine sarcoid?

Histopathology​

20

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

Benign​

21

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

Malignant​

22

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

Perineum or ventral surface of the tail

23

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

Cimetidine

A image thumb
24

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

False

Dark-skinned cattle are more commonly affected