Equine Melanoma

Question 1

What tumors arise from the malignant transformation fo normal melanocytes?

Answer 1

Melanoma

Question 2

What is the second most common equine tumor?

Answer 2

Melanoma

Question 3

What horses are predisposed to melanoma?

Answer 3

Gray and old horses

Question 4

Where are the most common areas of melanoma formation?

Answer 4

Perineal region
Ventral tail
lips

Question 5

What confirms a melanoma diagnosis?

Answer 5

biopsy

Question 6

What sx tx is best for removal of melanoma in the eye region?

Answer 6

Sliding flap technique

Question 7

What is the max amount of tissue that can be undermined when doing the sliding flap technique?

Answer 7

4cm- any more and the tissue will slough

Question 8

What are some other tx options for melanoma besides sx?

Answer 8

Radiation
Intratumoral injections
Systemic (non-specific…Cimetidine)

Question 9

T/F: Melanomas can start benign and turn malignant

Answer 9

TRUE

Question 10

What is the greying process due to in equine melanoma?

Answer 10

Autosomal dominant trait that is associated with an increased risk of melanoma and vitiligo

Question 11

What fraction of untreated benign melanoma tumors can progress to malignant behavior?

Answer 11

2/3

These are capable of local invasion and widespread metastasis

Question 12

How does metastasis of melanoma occur?

Answer 12

hematogenous or lymphatic spread to any region of the body

Question 13

How are equine melanomas typically diagnosed?

Answer 13

Physical appearance of tumors and signalment

Biopsy can provide definitive diagnosis

Question 14

What is intratumoral chemotherapy?

Answer 14

Injection or placement of cytotoxic drugs directly into the tumor or peritumoral tissue
high drug concentrations to the tumor