Salivary Gland Adenocarcinoma
Saliva contains many useful enzymes that help in the digestive process. These enzymes increase solubility of food by lubricating the contents. There are four major salivary glands, including the mandibular, sublingual, parotid, and zygomatic gland. Adenocarcinoma can affect any of these salivary glands in cats, but the major target of this tumor in cats is the parotid gland, the largest of the salivary glands. Adenocarcinoma of the salivary gland is highly metastatic and can metastasize into distant organs and tissues in the body. Siamese cats are at higher risk as compared to other breeds, and male cats are affected twice as much as compared to female cats. Like other adenocarcinomas, adenocarcinoma of the salivary glands usually affects cats older than eight years.
Symptoms and Types
Symptoms of adenocarcinoma of the salivary glands depends upon the type of salivary gland that is affected. Following are a few of the common symptoms related to salivary gland adenocarcinoma:
- Painless swelling of the upper neck, ear base, or upper lip
- Halitosis (foul breath)
- Weight loss
- Poor appetite
- Dysphagia (difficulty in swallowing)
- Exophthalmos (bulging of the eye)
- Dysphonia (hoarseness)
The exact cause is still unknown. This disease is classified as idiopathic.
Your veterinarian will perform a thorough physical exam on your pet, taking into account the background history of symptoms. Blood tests, biochemical profiles and urinalysis will be performed, though results will often return as normal with this disease. Radiographs of affected areas and bones can reveal important information about the nature and extent of the problem. X-rays of other regions may also be performed to see if the tumor has metastasized into these regions of the body, and more refined procedures, like tissue biopsy, will help in establishing a confirmatory diagnosis.
Unfortunately, there is no definitive treatment available for adenocarcinoma of the salivary glands in cats. Surgery to excise and remove the tumor along with some adjacent normal tissue is often recommended. After surgery your cat may be recommended for radiotherapy to achieve local control and long-term survival. No chemotherapeutic agent has yet been recommended for salivary gland adenocarcinoma. Multiple surgeries may be required along with the subsequent radiotherapy sessions.
Living and Management
Patients that have undergone surgery may need to be taken for veterinary evaluations every three months. Surgery combined with radiotherapy can improve survival time for up to several months in cats. You can improve the quality of life for your cat during this period by keeping stress at a minimum for your cat, and making it as comfortable as possible to minimize pain and other associated complications. Your cat will need special attention in proper nutrition and pain control. Your veterinarian will guide you in planning for meals and in choosing the best remedies for pain.