Exam 7 L. 12 Flashcards
Oral tumors
1) most are malignant
2) cats environment may cause SCC
- eating tuna, eating canned food, flea collars, living indoors with smokers
3) dogs environment may cause tonsil SCC
- living in urban areas
Common oral tumors
ORAL TUMORS ARE THE 4TH MOST COMMON CANCER IN DOGS!!!
Dogs: Malignant melanoma»_space;squamous cell carcinoma >fibrosis sarcoma
Cats: squamous cell carcinoma >fibrosarcoma
Oral tumors… But remember:
1) benign oral lesions are more common, particularly in younger animals
2) dog: tooth-root abscess, gingival hyperplasia, granulomatous or dental disease
3) Cat: foreign body, granulomatous disease
Oral tumor clinical signs
1) often discovered during routine dental work associated with loose teeth
2) *gingival swelling most common
3) oral mass, pain with opening mouth, oral hemorrhage, poor appetite, dysphagia, weird teeth, blood in the food bowl, weight loss
4) Ptyalism common in cats
5) swelling noted below the eye or along the jaw
6) other signs may include epistaxis, sneezing, mucopurulent nasal discharge
Remember: mast cell tumors
Mast cell tumors usually do NOT go to lungs!
-MCT go to lymph node, spleen, and liver
Non-pigmented oral melanoma
Approximately 30% of oral melanomas may be amelanotic
Biopsy
1) biopsy or remove even negative lymph nodes
-melanoma: 40% may have normal-size lymph nodes
BIOPSY BIOPSY BIOPSY
Extent of disease tab
1) >1/2 of gingival cancer has bone involvement!
2) oral radiographs show bone lysis (need at least 60% bone lysis to see it on radiograph)
Workup plan for oral cancer
1) detailed information on the location of the primary tumor
2) accurate tumor measurements and lymph node evaluation by cytology or biopsy
3) careful evaluation for metastasis by thoracic radiographs, CT, or MRI
Control of oral tumor
1) surgical excision for local control
2) 2 cm margins recommended, but may be difficult
3) regional lymph nodes removed with histopathology performed
4) local control for squamous cell carcinoma and melanoma, but need chemotherapy/immunotherapy for metastatic disease
local recurrence more common with maxillectomy ==> hard to get 2 cm margins!
Oral melanoma
1) brown-black, ulcerated, 30% amelanotic (behave the same and just as aggressive)
2) smaller weight dogs: Scottish Terriers, goldens, poodles, Daschunds
3) usually older dogs but can be young
4) aggressive behavior of digit, footpad, mucocutaneous junctions, oral
* *oral: 40% microscopic metastasis at diagnosis**
Oral malignant melanoma
Treatment: surgery alone - size matters
radiation therapy may be helpful (especially if <5 cm or microscopic disease)
Negative prognostic indicators: oral malignant melanoma
1) caudal location in the mouth
2) greater bone lysis seen
3) large size/tumor volume-larger is worse
4) metastasis
5) histologic grade - high-grade (more mitoses, poorly differentiated tumors behave more aggressively)
Merial melanoma vaccine
1) using the gene for human tyrosinase, we can induce antibody against the dog’s tyrosinase (present on melanoma cells)
* *this vaccine is aimed at stimulating immune response versus micro-metastatic disease and preventing the micromets from becoming macromets**
==== Used after surgery (MST >1 year or more)
Oral squamous cell carcinoma
1) larger dogs
2) ulcerated, frequently invade bone
3) SCC rostral = better prognosis; SCC on tonsil = short prognosis
4) size matters
5) piroxicam may improve survival
2nd most common malignant oral tumor in the dog
