Oral SCC in cats is well known and not so uncommon disease. Early disease recognition ant treatment is mandatory. Considering Squam Cell Carcinoma require a great surgical dose, have a low metastatic risk but high local recurrence risk, correlated with a small mouth overall area in cats, even a reduced, subcentimetrical lesion requires at least 1 cm in all directions plus the area of the initial lesion, meaning more than 2.5-3 cm, a large surgery for any cat. This is the case of a 13 y old cat, male, castrated, with prior biopsy and SCC confirmation. Owner discussion and adherence is essential for any following treatment option. In this case, at the time of oncology and surgery method discussion there were bone invasion evidence and soft tissue ivolving the median line of the mandible. In result, it is proposed a radical mandibulectomy, the one called “surgeon pushing the limits”, involving left or right mandible and behind the canine of the other mandible. this is a large, radical, high-risk surgery for cats as many of them do not eat by themselves after surgery for the entire life, so potentially a patient with high after surgery requirements or even euthanasia indication. For this patient, even though the non-mobile intermandibular joint acts as a border for SCC, the soft tissue seams to go at least beyond this line and there is no way to scrap the soft tissue off the bone and to let this tissue in place to heal. So, the most radical, most extensive surgery is employed in order to try to secure best chances to stay off any recurrence or metastasis, which may mean a very poor prognosis and maybe early death of low quality of life following aggressive local disease. Even if regular mandibulectomy offer the choice of a some limit for soft tissue excision, in this case I chose to include all visible soft tissue involved with an en-block excision wit the skin, subcutaneous, muscle, mucosa, bone involved and all other tissues in order to minimize the risk of local recurrence.
As a first step, the cat is positioned in dorsal recumbency, a caudal at least 1 cm margin is drawn, as this is one of the most difficult to achieve in oral oncology surgery. Bone tissue is isolated and a bone cutter is used to cut on the mandible. This is one advantage due to the possibility to preserve the mandibular canal viscera and to address them in a later step with any surgical mean. Bone canal is occluded with special bone wax, with excellent local homeostasis. Nest bone cut is beyond the contra-lateral canine mandible tooth considering soft tissue involvement. Soft tissue is easy to incise and fair surgical closure is achieved. In cats, as in any animal, if nutritional support is needed or suspected, all measures may be employed. In this case, before surgery ending we chose to put in place a esophagostomy tube for nutritional support. Statistically this is an all poor prognosis. Contrary to all odds the cat started to eat or show voluntary eating behavior two days after surgery. Local edema, pain, drooling, reduced hemorrhage, tongue movement disorders, swallowing difficulties, minor depression all came at least five days after surgery. Multimodal pain madication is mandatory for at least 3-4 days. Infection control is an medium risk as local vasculature can provide most of the immune cells required. As with most madibulectomies, some of the complications are dehiscence, salivary cysts, drooling, pain, edema, secondary surgery, reconstruction, tooth abscess, bone edge exposure, suture or tissue failure and so on. In this case, local edema, pain, drooling and dehiscence are observed with bone edge exposure days after surgery. Local debridement and suture solves part of the problem. Secondary dehiscence is following and a secondary intention healing is followed with rewards. local soft tissue granulation is observed and between 45 and 60 days after surgery all bone edges are covered with healthy mucosa, eating is normal, behavior is as previous, owner interaction is satisfactory, aesthetic is more than fair, no recurrence or metastasis, wide clean surgical margins on pathology report. Radical surgery, aggressive tumor, high risk, good outcome, courageous owners, dedicated team, poor prognosis, happy ending so far.
de Dr. Daniel Lescai
Doctor in Medicina Veterinara