Oral tumours

Question 1

what are the characteristics of oral tumours?
what are the most common ones in dogs and cats?
what are the other types of tumours of the mouth?

Answer 1

Most tumours of the oral cavity are malignant
* Malignant melanoma and squamous cell carcinoma most common in dogs
* Squamous cell carcinoma most common in cats

Other malignant tumours include:
* Fibrosarcoma
* Osteosarcoma
* Multilobular osteochondrosarcoma

Question 2

what are the two types of melanoma of the mouth?

Answer 2

Question 3

what is the sampling differnces of oral melanomas and squamous cell carcinomas?
what are the benefits of biopsy?

Answer 3

melanoma need to FNA as mucosal surface is intact
squamous cell carcinoma has a broken down mucosa so can do an impresson smear
* biopsy allows for grading

Question 4

Benign tumours on the oral cavity are also common and include what?

Answer 4

• Acanthomatous ameloblastoma
• Peripheral odontogenic fibroma - typically dogs over the age of six (but can be seen at any age), rare in cats

used to be called epulis (epuli) - fibrous tumour of the mouth - needs biopsy for classification (could be malignant)

Question 5

how are oral tumours managed?

Answer 5

Surgery is the mainstay treatment for the majority of malignant and benign tumours

Treatment options depend on the location of the tumour and on the type (biology) of the tumour
* benign tumours excised with 1 cm margins
* Malignant tumours excised with 2-3 cm margins
* Mandibulectomy
* Maxillectomy

Other treatments options (instead or in addition to surgery) include:
* Radiation therapy
* Chemotherapy
* Immunotherapy - melanomas in dogs

Question 6

what are the clinical signs of oral tumours?

Answer 6

• Presence of a mass in the oral cavity
• Increased salivation, blood in the saliva, odorous breath
• Swelling on the face or bulging of the eye (exophthalmos)
• Bloody nasal discharge
• Difficulty eating or pain on opening the mouth, weight loss and enlarged lymph nodes in the neck region
• Loose teeth, especially in animals with general good teeth, may be indicative of cancer-induced bone loss, especially in cats

Question 7

how are oral tumours diagnosed?

Answer 7

• Physical examination
  
  • Concomitant problems
  • Size and site of oral mass
  • Evaluation of regional lymph nodes
• Blood tests
• FNA
  
  • Often non-diagnostic as requires the lesion to exfoliate
• Core biopsy
  
  • Histopathology (bony lesions might prove difficult to obtain representative sample)
• Imaging of the skull
  
  • Conventional radiography
  • Ideally, CT scan
• Staging
  
  • Conventional radiography
  • Ideally, CT scan

Question 8

What is the surgical aftercare after oral surgery?
what are the postoperative complications?
what are the outcomes of fibrosarcomas and benign tumours?

Answer 8

Most animals discharged 2-5 days after surgery, depending on level of surgery, comfort and ability to eat soft food
Return for re-check 7-10 days postop
Restrictions
* Analgesia
* Antibiotics
* Restrictive (Elizabethan) collar to prevent self-traumatisation
* Limited exercise
* Soft canned food or soaked kibble for 2-3 weeks postop
* No chews, raw hide or chewing toys for at least 3-4 weeks postop

complications:
* Incision breakdown requiring further surgery to repair
* Bleeding from the nose following maxillectomy
* Increased salivation – may persist for some weeks
* Mandibular drift following mandibulectomy
* Difficulties eating – usually not a problem in dogs but a common problem in cats
* Recurrence of tumour

outcome:
- fibrosarcoma continues to have high local recurrence rate requiring adjunctive radiation therapy or further surgery
- Benign tumours may be cured as long as clean margins have been achieved