Oral Tumours Flashcards
Who is most likely to get oral tumours?
A male sex predisposition has also been reported for dogs with malignant melanoma and tonsillar squamous cell carcinoma (SCC).
Dog breeds with the highest risk of developing oropharyngeal cancer include the cocker spaniel, German shepherd dog, German shorthaired pointer, Weimaraner, golden retriever, Gordon setter, miniature poodle, Chow Chow, and Boxer
What are the most common oral tumours?
In dogs, the most common malignant oral tumors are, in descending order, malignant melanoma, SCC, and fibrosarcoma
Other malignant oral tumors in dogs include osteosarcoma, chondrosarcoma, anaplastic sarcoma, multilobular osteochondrosarcoma, intraosseous carcinoma, myxosarcoma, hemangiosarcoma, lymphoma, mast cell tumor, and transmissible venereal tumor
In cats, SCC is the most common, followed by fibrosarcoma
What is the common signalment for malignant melanoma
ends to occur in smaller body weight dogs. Cocker spaniel, miniature poodle, Anatolian sheepdog, Gordon setter, Chow Chow, and golden retriever are overrepresented breeds. A male predisposition has been reported
How does malignant melanoma spread?
highly malignant tumor with frequent metastasis to the regional lymph nodes and then the lungs. The metastatic rate is site, size, and stage dependent and reported in up to 80% of dogs
What is a new therapy technique for malignant melanoma
Immunotherapy - there is a vaccine
What increases the risk of SCC in cats
significantly increased by over 3.5-fold with the use of flea collars and high intake of either canned food in general or canned tuna fish specifically
How does SCC progress?
SCC frequently invades bone in both cats and dogs, and bone invasion is usually severe and extensive in the cat. Increased tumor expression of parathyroid hormone–related protein in cats with oral SCC may play a role in bone resorption and tumor invasion. Paraneoplastic hypercalcemia has also been reported in two cats with oral SCC. Metastasis in the cat is rare and the true incidence is unknown because so few cats have had their local disease controlled; thus an accurate estimate of the metastatic potential has not been confirmed
How malignant is fibrosarcoma?
Oral fibrosarcoma will often look surprisingly benign histologically and, even with large biopsy samples, the pathologist can find it difficult to differentiate fibroma from low-grade fibrosarcoma. This syndrome, which is common on the hard palate and maxillary arcade between the canine and carnassial teeth of large-breed dogs, has been termed histologically low-grade but biologically high-grade fibrosarcoma
Fibrosarcoma is locally invasive but metastasizes to the lungs and occasionally regional lymph nodes in less than 30% of dogs
How do you treat fibrosarcoma?
Even with a biopsy result suggesting fibroma or low-grade fibrosarcoma, the treatment should be aggressive, especially if the cancer is rapidly growing, recurrent, or invading bone.
What are epulides?
Epulides are benign gingival proliferations arising from the periodontal ligament and appear similar to gingival hyperplasia. Three types of epulides have previously been described in the dog: acanthomatous, fibromatous, and ossifying. However, the terminology for these tumors has changed; acanthomatous epulis is now termed acanthomatous ameloblastoma and peripheral odontogenic fibroma is the preferred nomenclature for fibrous and ossifying epulides
When can you see bone lysis?
Bone lysis is not radiographically evident until 40% or more of the cortex is destroyed
Outline surgical therapy of oral tumours
Surgery and RT are the most common treatments used for the local control of oral tumors. Surgical resection is the most economic, expeditious, and curative treatment. The type of oral surgery depends on tumor histology and location. Except for peripheral odontogenic fibromas, most oral tumors have some underlying bone involvement and surgical resection should include bony margins to increase the likelihood of local tumor control.
Margins of at least 2 cm are necessary for malignant cancers such as SCC, malignant melanoma, and fibrosarcoma in the dog
Outline chemotherapy for SCC in dogs
Piroxicam does appear to have some effect against oral SCC in dogs, and response rate is improved when piroxicam is combined with either cisplatin or carboplatin
Outline prognosis with malignant melanoma
guarded. Metastatic disease is the most common cause of death with metastasis to the lungs reported in 14% to 67% of dogs.* Surgery or RT can provide good local control
What is the px for SCC in dogs
Surgery is the most common treatment for non–tonsillar SCC.11 Following mandibulectomy, the local recurrence rate is 10% and the MST varies from 19 to 26 months with a 91% 1-year survival time.
