Cancer of the Lymphocytes in Cats
Lymphoma is a type of cancer that originates in the lymphocyte cells. A type of white blood cell, lymphocytes play an important and integral role in the body's defenses in the immune system.
There are two forms of lymphocytes: B and T cells. Lymphoma may involve neoplastic proliferation of T or B, or non-B/non-T type lymphocytes, occurring primarily in the bone marrow, lymph nodes, and visceral organs.
Lymphoma is found to be responsible for around 90 percent of blood cancers and account for about 33 percent of all tumors in cats. Moreover, it is the most common cause of hypercalcemia in cats.
Symptoms and Types
Symptoms are highly variable and depend upon the anatomical form of this tumor. Following are some forms of lymphoma along with the related symptoms in cats:
Multicentric form (
(occurs in the lymph nodes)
- Swollen lymph nodes (i.e., jaw, under arms, groin)
- Loss of appetite
- Weight loss
Solitary form )
- Symptoms depend upon location
The incidence of lymphoma is believed to be associated with exposure to feline leukemia virus (FeLV) and the feline immunodeficiency virus (FIV). Cats that have been infected with either of these viruses have a significantly higher rate of lymphomas than the general cat population.
You will need to give your veterinarian a thorough history of your cat's health and onset of symptoms. The history and details you provide may give your veterinarian clues as to which organs are being primarily affected. Knowing a starting point can make diagnosis that much easier to pinpoint. Once the initial history has been taken, your veterinarian will perform a complete physical examination on your cat. Routine laboratory testing includes a complete blood count, biochemistry profile, and urinalysis.
The blood test results may show anemia, or the presence of an abnormally high number of lymphoblasts in the peripheral blood, a condition called lymphoblastosis. Lymphoblasts are immature cells which differentiate to form mature lymphocytes; they are normally present in the bone marrow, but if they proliferate uncontrollably they may migrate to the peripheral blood, resulting in the abnormal condition called lymphoblastosis.
Biochemistry profiling may show an abnormally high creatinine, serum urea nitrogen, liver enzymes, and calcium levels. The urinalysis may reveal abnormally high levels of pigment bilirubin and proteins in the urine. Affected cats are also tested for the feline leukemia virus (FeLV), which is frequently associated with lymphomas. Your veterinarian will also use diagnostic imaging to locate the tumor(s), conducting X-rays of various body regions, especially the region that appears to be affected. A biopsy of the bone marrow will help in confirming the diagnosis conclusively.