Malignant Neoplasia

Question 1

SCC

Answer 1

Second most common oral tumor in dogs and first in cats (70%)
Mean age 8 - 9 yo
Low met rate
Proposed causes include chronic exposure to air pollution, tobacco smoke, papillomavirus infections, flea collars, diet, prior radiation exposure, and chronic mucosal and/or periodontal inflammation.
Much higher frequency in urban settings
Large dogs appear to be more frequently affected than smaller dogs.

Prognosis is significantly worse in cats then in dogs

Question 2

Common locations of SCC

Answer 2

Gingiva, tonsil, oral mucosa, lip, palate, pharynx and tongue

Question 3

Piroxicam can be used for

Answer 3

SCC
Cox-2 inhibitor

Question 4

Lingual SCC

Answer 4

Most common tumor in the tongue
Typically, bilateral and symmetrical, diffusely infiltrates the thickness of the tongue, and involved the rostral two-thirds of the tongue.
Most common presenting signs – excessive drooling and oral bleeding
Metastatic rate are higher. 14 - 37%.
Survival without treatment is 1 month.
Survival with surgery alone is between 6 and 39 months
Survival with radiation is between 6 – 26 months

Culp, Withrow et al JAVMA 2013 – 97 dogs with lingual neoplasia
28% dogs had recurrence, 19% of dogs had metastatic disease
Dogs with tumors <2cm had longer survival times after glossectomy – importance of early detection.
SCC MST 216 days

Question 5

Tonsillar SCC

Answer 5

More at risk in urban environment.
Generally, arises from the crypt epithelium, with cords or islands of epithelium invading the underlying lymphoid tissue.
Metastasis rate are high. 61.1 – 97%
Can see mets in contralateral LN as well as lung, liver, spleen, pericardium and heart, ribs, kidney, cranial mediastinal and pancreatic lymph node.

Question 6

PSCC

Answer 6

Affects younger dogs (2-5months) but may occur in adults up to 9yo. (2 studies think older dogs)
Tumors appear locally aggressive with underlying bone lysis.

Rostral maxilla was most common site
Invasion of underlying bone and lymphadenopathy were evident on CT in most dogs
No evidence of mets found
Surgical excision with 1-2cm margins were complete in all cases with tumor-free interval of 12 months

Question 7

Melanoma

Answer 7

most common oral tumor in dogs
Common sites: gingiva, labial mucosa, palate, buccal mucosa and tongue

High met rate
MST about 335d

Question 8

Fibrosarcoma

Answer 8

3rd most common malignant tumor in the dog
2nd most common malignant tumor in the cat

More common in lg breed vs sm breed dogs

Gingiva, hard palate, labial mucosa, soft palate, tongue
Tends to present as broad-based, firm swelling

High level of recurrence

Question 9

Histo low grade, Bio High grede

Answer 9

golden retrievers

Surgical margins of at least 2cm.

wide surgical resection and radiation therapy appears to provide the best survival rates

Question 10

Osteosarcoma

Answer 10

medium-large breed dogs
mean age 9.5 years (range 3–15 years) 10 years
male to female ratio 1:1.8.

Mandibular OSA may have better prog than appendicular OSA
MST has been reported as 525 days and 58% of dogs develop mets

Question 11

Malignant Peripheral Nerve Sheath Tumor

Answer 11

Uncommon tumor of the oral cavity

Manifests as a diffuse, poorly delineated mass involving a large portion of the mandible and maxilla

Bone loss on rads
Challenge to prevent local recurrence due to tracking along the nerve sheath

Tx: Radical Sx - >2cm for possible cure