Malignant lymphoma associated with experimentally induced feline immunodeficiency virus infection.

A malignant low-grade B-cell lymphoma, primarily in the kidney, is described in a specific-pathogen-free cat experimentally infected with feline immunodeficiency virus (FIV) and free of feline leukaemia virus. At the time of diagnosis the cat showed a marked reduction of circulating CD4+ T lymphocytes, was 2 years old, and had been infected for 18 months. FIV was isolated both from peripheral blood mononuclear cells and the neoplastic tissue. DNA of FIV gag gene was detected in several specimens, including the neoplastic tissue. Even if they do not demonstrate a direct role for virus promotion of lymphomas, these and previous observations indicate that B-cell malignant lymphoma might be associated with FIV infection as reported for human and simian immunodeficiency virus infections.