Educational Articles

Cats + Tumors

  • Melanocytes are cells that produce a pigment called melanin. They are found in many parts of the body where there is pigment, particularly the skin, hair and eyes.

  • A 'tumor' is a lump. Some tumors are cancerous and some are benign. There are several different types of tumors that occur in the tissues around the eye. Many of these tumors have physical effects on the eye, causing soreness, redness and weeping. The most common treatment for tumors around the eye is surgical removal of the lump.

  • Fibrosarcoma is a tumor originating from the fibroblasts of the skin and subcutaneous connective tissue. The tumors vary in growth rate.

  • It is important to recognize that multiple tumors in the liver are not always cancers. The livers of older dogs may become nodular without causing any clinical effects.

  • The liver has a massive blood supply so many cancer cells from elsewhere arrive within it and start to grow. In dogs, metastatic tumors are three times as common as primary tumors and over 30% of malignant cancer may metastasize to the liver.

  • Most primary lung cancers originate from the epithelium lining the airways. In dogs, most develop in the alveoli where oxygen is taken up into the body, but in people and in cats most originate in the main airways (bronchi).

  • Lymphatic tumors are rare in pets. Lymphangiomas are benign and lymphangiosarcomas are malignant and have a moderate-to-high metastatic potential. Patients with lymphatic tumors typically have severe edema because of lymphatic obstruction. These types of tumors occur more frequently in young dogs and cats. Treatment usually involves surgical excision and chemotherapy may be used as a follow-up treatment in the case of lymphangiosarcomas.

  • Lymphocytes are specialized cells that function as part of the body's immune system, and are key cells in the body's ability to fight and prevent infection. Lymphocytes are found in the blood and tissues throughout the body, and are in particular concentration in lymph nodes and other 'lymphoid tissue'.

  • Lymphoma is a cancer of the lymphocytes. Lymphocytes are cells that are involved in the immune system. Lymphoma is connected with feline leukemia, a viral infection. Feline lymphoma most commonly affects the intestines. Therefore, clinical signs of lymphoma are often similar to other intestinal diseases. Diagnosing lymphoma requires finding cancerous cells on microscopic examination. Lymphoma cannot be prevented, but the likelihood of a cat developing lymphoma can be decreased by preventing feline leukemia virus infection.

  • The most common forms of cutaneous lymphoma are epitheliotropic lymphoma and dermal lymphoma. No specific risk factors or causes have been identified in the development of cutaneous lymphoma. Generally, cutaneous lymphoma can appear as various-sized irritated, ulcerated, or infected patches anywhere on the skin, including the gums, nose, or lip margins. These areas may become ulcerated and bleed, or become crusted. Secondary infections are possible. By far, the most common treatment for cutaneous lymphoma is chemotherapy. Unfortunately, the response to treatment, although initially encouraging, is typically short-lived, with gradual return of the tumors.