Tumors of the Skin

Question 1

Malignant neoplasm of keratinocytes that is locally invasive and slow to metastasize and assoc. w/chronic sun exposure

Answer 1

SCC

Question 2

Where do skin SCCs usually occur in cats?

Answer 2

Head

Question 3

If an SCC is found on a cat’s digit, what is the next step?

Answer 3

Thoracic rads b/c SCC in cats may be 2* to pulmonary carcinoma

Question 4

Where do skin SCCs usually occur in dogs?

Answer 4

Digit, trunk, limbs, scrotum

Question 5

Benign tumor caused by infection of epithelial cells w/species-specific papillomaviruses

Answer 5

Papilloma

Question 6

How is papillomavirus transmitted?

Answer 6

Direct and indirect contact

Question 7

What is the incubation period of papillomavirus?

Answer 7

1-2mo

Question 8

Which age of dogs are most commonly affected by papillomavirus?

Answer 8

Younger

Question 9

How soon do most papillomas regress?

Answer 9

3mo

Question 10

How do papillomas present?

Answer 10

Smooth white papules, plaques, or cauliflower lesions

Question 11

What regions of the body are commonly affected by papillomas?

Answer 11

Nose, conjunctiva, and haired skin

Question 12

What is the origin of a lipoma?

Answer 12

Adipocyte

Question 13

Are lipomas malignant or benign?

Answer 13

Benign

Question 14

Are lipomas more common in dogs or cats?

Answer 14

Dogs

Question 15

Where are lipomas most often found on the body?

Answer 15

Thorax, abdomen, proximal limbs

Question 16

What do lipomas look like?

Answer 16

Soft, dome-like mass, can be pedunculated

Question 17

Are sebaceous gland tumors more common in dogs or cats?

Answer 17

Dogs

Question 18

What do sebaceous gland tumors look like?

Answer 18

Nodular, solitary, wart-like

Question 19

Malignant tumor of dermal mast cells

Answer 19

Mast cell tumor

Question 20

What is the pathogenesis of a mast cell tumor?

Answer 20

P53 and c-KIT mutation

Question 21

Why might an MCT dog also have a coagulopathy?

Answer 21

Heparin in the mast cells

Question 22

Reactive hyperplasia that originates from langerhans cells

Answer 22

Cutaneous histiocytoma

Question 23

Single well circumscribed mass on the head, pinnae, or limbs of a young dog

Answer 23

Cutaneous histiocytoma

Question 24

How do you treat a cutaneous histiocytoma?

Answer 24

None - spontaneously regress in 3mo

Question 25

Are fibrosarcomas more common in dogs or cats?

Answer 25

Cats

Question 26

What do fibrosarcomas originate from?

Answer 26

Dermal/subcutaneous fibroblasts

Question 27

Which vaccines are most often assoc. w/fibrosarcomas?

Answer 27

Rabies and FeLV

Question 28

Are basal cell tumors more common in dogs or cats?

Answer 28

Cats

Question 29

Are basal cell tumors more often benign or malignant?

Answer 29

Usually benign

Question 30

Large dog presenting with a “skin tag” after trauma likely has what type of skin tumor?

Answer 30

Fibrovascular papilloma

Question 31

Firm pedunculated growths commonly found on bony prominences, sternum, and trunk of dogs

Answer 31

Fibrovascular papilloma