Neoplasia of the Oral Cavity

1
Neoplasia of the Oral Cavity

• Elaina Turner

2
List 2 common benign tumors and 4 common
malignant tumors of the oral cavity in dogs.

• Benign
• Papilloma
• Epuilis fibrous, ossifiying, acanthomatous
• Malignant
• Melanoma
• Squamous cell carcinoma
• Fibrosarcoma

3
Which tumors are more common in small dogs, and
which in large dogs?

• Small dogs melanoma and non-tonsillar squamous
  cell carcionoma
• Large dogs fibrosarcoma

4
What tumor occurs most often in middle aged dogs?

• Fibrosarcoma (4 to 5 yrs)

5
What are the most common tumors of the oral
cavity in cats?

• Benign none
• Malignant
• Squamous cell carcinoma
• Fibrosarcoma

6
What is the prognosis for each of these tumors in
dogs and in cats?

• Papilloma excellent
• Epulis
• Fibrous
• Ossifying
• Acanthomatous good
• Melanoma median survival 7-8mths, lt25 alive
  after 1yr
• Squamous cell carcinoma gingival in dog fair
  to good in cats poor tonsillar lt10 at one year
  
• Fibrosarcoma - guarded to poor

7
What criteria are evaluated in staging oral
tumors?

• Size of tumor
• Presence of bone invasion
• Evidence of LN involvement (ipsilateral,
  contralateral)
• Presence of distant metastasis

8
Discuss the tx of an early acanthomatous epulis
that has not destroyed the underlying bone.

• Radiation alone or local excision radiation

9
How would your tx differ if bony desctruction has
occurred?

• A partial mandibulectomy or maxillectomy would be
  indicated

10
For which of the common oral malignancies in dogs
will FNA be most diagnositic? Least?

• Diagnostic
• Melanoma
• Least
• Fibrosarcoma

11
Why is the hemimandible usually removed for in
treating melanoma, although the tumor is unlikely
to damage the bone?

• Because the tumor readily metastises and thus
  wide margins are required.

12
Why is tx of this tumor seldom successful?

• Because of the high rate of metastasis to the
  lungs and regional lymph nodes

13
Compare squamous cell carcinoma of gingival
origin and of tonsillar origin in regard to bony
invasion distant metastasis sensitivity to
radiation prognosis.

• Bony invasion
• Gingival ? highly osteolytic
• Tonsillar ? not/less osteolytic
• Distant metastasis
• Gingival ? low rate
• Tonsillar ?high rate
• Sensitivity to radiation
• Gingival ? sensitive
• Tonsillar ? controls local dz but of little long
  term benefit
• Prognosis
• Gingival ? fair to good, 50 controlled locally
  gt1yr
• Tonsillar ? lt10 survival at one year

14
In what way does surgical removal of fibrosarcoma
fail?

• Often recurrs

15
What is the usual cause of death?

• Euthansia owner tired of the roller coaster
  sx its gone, its back, sx its gone, back again
• When animal has difficulty eating

16
What are the limitations of partial glossectomy
in the dog?

• Not well tolerated in cats
• Amputation at base of tongue may require
  hand-feeding
• Amputation of 40-60 of the tongue is the max

17
What other tx option is used for tumors of the
tongue?

• Radiation therapy

18
Which of these tumors has the best prognosis?

• Granular cell myoblastoma with 82 with local
  control at one year post treatment.

19
Why is cheiloplasty recommended following
hemimandibulectomy?

• Perform cheiloplasty to level of 2nd premolar to
  prevent prolapse of tongue

20
What is mandibular drift?

• When the remaining hemimandible deviates medially
  
• May cause trauma to the palate or gingiva.
  Malocclusion, TMJ problems

21
What can be done to prevent or limit this
complication?

• No way to prevent
• Treat by tooth extraction

22
What are two possible complications that must be
considered before maxillectomy procedures?

• Reconstruction may be difficult, esp if lesion
  crosses midline of palate or with caudal partial
  maxillectomy
• Temporary bilateral carotid artery ligation is
  used to minimize intraoperative hemorrhage