Clinical Oncology Service Veterinary Hospital of the University
of Pennsylvania Last Modified: November 1, 2001 Lymphosarcoma
(lymphoma) is one of the most common cancers diagnosed in cats.
It is a cancer of the lymphocytes (a type of blood cell) and
lymphoid tissues. Lymphoid tissue is normally present in many
places in the body including lymph nodes, spleen, liver,
gastrointestinal tract and bone marrow. The feline leukemia
virus (FeLV) has been shown to cause lymphosarcoma in cats. We
believe that the feline leukemia virus is responsible for many
of the cases of lymphosarcoma. Cats with the feline
immunodeficiency virus (FIV) are also at higher risk of
developing lymphosarcoma. Cats of any age, breed and sex can be
affected. We typically see lymphosarcoma in younger cats that
are infected with the feline leukemia virus, and in older cats
that are not infected with the virus. Lymphosarcoma can be
divided into several different forms, which depend upon the
primary (predominant) site of the tumor. Some cats h