Skin Cancer (Squamous Cell Carcinoma) in Cats

Cutaneous Squamous Cell Carcinoma in Cats

The epidermis, or skin, consists of several layers. The outer layer is made up of scale like cells called the squamous epithelium. This layer of tissue covers the surface of much of the body, and lines the cavities of the body. A squamous cell carcinoma is a type of cancer that originates in the squamous epithelium. It may appear to be a white plaque, or a raised bump on the skin. Often the raised mass will necrotize in the center and ulcerate, with occasional bleeding.

As carcinomas are characteristically malignant and particularly invasive, it is essential to have this form of skin cancer diagnosed and treated without delay. Cutaneous squamous cell carcinomas are typically fast growing tumors that get bigger with time and resist healing. Some cats can get as many as thirty sores on their skin, a condition called Bowen’s disease. Both types of squamous cell carcinoma can metastasize to other organs. If the ulcers are diagnosed before they have had an opportunity to become malignant, this condition may be treated effectively in some cases.

Squamous cell carcinomas are seen more in cats that live at high altitudes and in cats that spend a lot of time in the sun. White cats and light colored cats are more likely to get these tumors than other kinds of cats. This kind of cancer is most commonly seen in older cats.

Symptoms and Types

• Ulcers
  • A crusty or bleeding sore on the skin that does not go away with antibiotics or creams
  • Sores that do not heal for several months
  • Sores in areas where the hair is white or light colored
• Bowen’s Disease
  • Skin that changes color and develops an ulcer in the center
  • Hair in the sore falls out easily
  • Dried, crusty material on the hair near the sore
  • As many as 30 sores on the head, neck and shoulders
• Growths or Tumors
  • White colored growth
  • Growths in areas where hair is white and skin is light colored
• Sores or growths may be found anywhere
• The most common locations are the front of the nose (nasal planum), eyelids, lips, and ear tips

Causes

• Long term exposure to sunlight/UV rays

Diagnosis

You will need to give your veterinarian a thorough history of your cat's health, onset of symptoms, and possible incidents that might have precipitated this condition, such as a recent fight that might have led to skin injuries, or a flea infestation that would have left open sores from vigorous scratching. Once this history has been detailed, your veterinarian will conduct a thorough physical examination on the cat, paying close attention to any growths on the skin or any sores that have not healed in several months. Your cat's lymph nodes will be palpated to determine if they are swollen, an indication that the body is fighting an invasive disease or infection, and a sample of lymph fluid will be taken for laboratory analysis. The presence of cancerous cells in the lymph glands will be indicative of metastasis through the body. Basic laboratory tests include a complete blood count and biochemical profile to confirm that your cat's organs are functioning normally.

Because carcinomas are characteristically malignant and metastasize quickly, your veterinarian may also order x-ray images of your cat's chest and abdomen so that a visual inspection can be made of the lungs and organs. Likewise, if your cat has a tumor on one of its legs, your veterinarian will want to take x-rays of the leg to see if the tumor has spread to the bone underneath it.

Standard biopsies will be taken of the growth or sore. This is the best way of determining exactly what kind of tumor your cat has.