Introduction
SCC has long been recognized to be the most common oral neoplasm, whereas melanoma has been the primary oral neoplasm in dogs. Recently, SCC has been reported to be the most common oral tumour in dogs as well.
Presentation
It is primarily found on the body of the jaws, but it can occur anywhere in the oral cavity. Physical look of the mass is not helpful; there is no possibility to establish any reliable diagnosis by gross examination. Therefore, before planning any surgery, information needs to be gathered to identify the type of tumour, the extent of the disease and whether or not it has spread.
Diagnosis and Staging of Tumours
Recent blood work (within a month)
Chest radiographs, 3 views
Biopsy of the mass - make sure it is deep and get bone, if at all possible. Obtain the biopsy through tissues that will be removed during the -ectomy surgery.
Harvesting of the lymph nodes on the ipsilateral side - If mass is maxillary, collect parotid and median retropharyngeal lymph nodes. If mass is mandibular, collect mandibular and median retropharyngeal lymph nodes.
Send biopsy and lymph nodes to a laboratory/pathologist you trust.
Imaging
Maxillary mass: CT scans are very helpful (would not go ahead these days without having one).
Mandibular mass: Intraoral radiographs will give you a good idea of the extent of the disease.
Lymph Nodes Harvesting
Refer to articles:
Smith M. J Vet Dent. 2002;19(3):122–126.
Smith M. J Vet Dent. 2002;19(3):170–174.
The mandibular lymph nodes are the easiest to collect and the parotid the hardest. The median retropharyngeal lymph nodes give trouble to surgeons fearful to go deep enough. It is situated deep to the jugular and just superficial to the carotid vessels. A pair of deep retractors eases the procedure tremendously.
Oncologic Surgeries
I am not going to rewrite the detail of each surgery. This can be found in the following texts:
Harvey CE, Emily PP. Small Animal Dentistry. WB Saunders.
Wiggs RB, Lobprise HE. Veterinary Dentistry: Principles and Practice. Mosby.
In: Manfra Maretta S, ed. Complications in Veterinary Dentistry.
Let me just stress some important points:
Before procedure: Start pain control. Use the multimodal approach. Blood type the patient and get a crossmatch with the donor bag. Make sure the blood is available before starting the surgery. Get a pre-op PCV.
During the procedure: Plan the closure before the first cut. Use laser scalpel anytime you can; it reduces bleeding, pain, and swelling. Cut bone with a high-speed handpiece and a sterile surgical length bur and/or with a chisel and a mallet. Ligate any large vessel as soon as possible. Remove the mass first, then elevate the flap for closure. Others (Dr. Mark Smith) elevate the flap before removing the mass. Both techniques work well. Eliminate dead space as much as possible. Use fine sutures; the tissues are not pulling, moving, or supporting much weight. Bury your knots so that there is little to irritate the patient. Stitch carefully and evenly so that there are no holes in the suture line. Get a post-op PCV.
After the procedure: Monitor recovering, make sure pain IS controlled. Recheck PCV 4 to 6 h post-op. Keep overnight.
Statistics
Squamous cell carcinoma in a study conducted by the author over an 8-year period in a referral facility:
Age range: 5 months to 17 years
Mean: 9.8 years
No gender bias in the presentations
Maxillas 41%, mandibles 48%, other 11%, dogs 65%, cats 35%
One-year survival: 60% for dogs, but only 33% for cats
Two-year survival: 57% for dogs, but only 17% for cats
Average survival without surgery: 3.5 months (9 were followed)
Points of interest: Survival times are longer than in older reports (one-year survival with surgery used to be 29% for dogs). Increase in survival due to better diagnostics and staging.