Oral tumours Flashcards
Where can oral tumours arise from?
- bone
- teeth
- soft tissue structures of the mandible, maxilla, or the tongue or pharynx
Are most tumours of the oral cavity benign or malignant? What are the most common ones in cats and dogs
- malignant
▪ Malignant melanoma and squamous cell carcinoma most common in dogs
▪ Squamous cell carcinoma most common in cats
Other examples of malignant tumours
▪ Fibrosarcoma
▪ Osteosarcoma
▪ Multilobular osteochondrosarcoma
Are benign tumours of the mouth common? Some examples
- yes
▪ Acanthomatous ameloblastoma
▪ Peripheral odontogenic fibroma
What is the mainstay tx for the majority of malignant and benign tumours?
- surgery
What other tx options are there (instead or in addition to surgery)?
▪ Radiation therapy
▪ Chemotherapy
▪ Immunotherapy
Are oral tumours common in the dog & cat?
- Oral tumours are relative common in cats and dogs
- Benign and malignant tumours of the oral cavity account for 3-12% of all tumours in cats and 6% of all tumours in dogs
Oral tumours – clinical signs
- 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
Oral tumours – diagnostics
- 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
Oral tumours – treatment options
- depend on the location of the tumour and on the type of the tumour
– benign tumours excised with 1 cm margins
– Malignant tumours excised with 2-3 cm margins - Mandibulectomy
- Maxillectomy
- Immunotherapy for melanoma in dogs
Partial mandibulectomy techniques
- Rostral hemimandibulectomy (unilateral rostral hemimandibulectomy)
- Rostral mandibulectomy (bilateral rostral hemimandibulectomy)
- Central hemimandibulectomy
- Caudal hemimandibulectomy
- Total hemimandibulectomy
- Three-quarter mandibulectomy
Partial maxillectomy techniques
- Hemimaxillectomy
- Rostral hemimaxillectomy
- Premaxillectomy (bilateral rostral hemimaxillectomy)
- Central hemimaxillectomy
- Caudal hemimaxillectomy
Epulis (most common tumour, what it is, signalment)
= old fashioned term for benign tumour in the mouth
- peripheral odontogenic fibroma
- Derived from cells of periodontal ligament
- tumour on the gingival or alveolar mucosa
- Typically, dogs over the age of six (but can be seen at any age)
- rare in cats
Segmental mandibulectomy/maxillectomy - use of metal plate
- can put in but likely to get infected and will then need removal
Surgical aftercare
- 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
Postoperative 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
- Rannula formation if affected the salivary gland with mandibulectomy
Outcome
- Tumour type and staging dependent
▪ e.g., 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
SCC appearance
- often erosive, esp in the cat
- likely to bleed
Are SCC radiosensitive?
- yes, so surgery then adjunct radiotherapy is often used
Which tumours of the mouth do and don’t exfoliate well?
- SCC do
- osteo- and fibrosarcomas don’t
What is mandibular drift?
- lower jaw moves to the side of the defect (following segmental mandibulectomy), can cause the lower canine tooth on the opposite side to stab into the upper hard palate
Ddx for oral SCC in the cat?
- stomatitis (immune mediated and benign)
What would you routinely place in a cat that has had oral surgery?
- O tube
