Although primary neoplasms of the kidneys are rare, lymphoma is the most common tumor affecting the kidneys of cats, and it is also common in other species. The lymphoma is usually multicentric and involves other tissues, including lymph nodes. In cats, there may be an association with feline leukemia virus. Destruction of renal tissue leads to azotemia and sometimes hypercalcemia. Microscopically, aspirated cells are typically large mononuclear cells with indented nuclei and often vacuolated cytoplasm. Complete clinical staging is recommended if the patient is considered a good candidate for chemotherapy. Prognosis of advanced multicentric disease is guarded.
See Neoplasia of the Urinary System in Small Animals in The Manual.
References
Wolfesberger B, Skor O, Hammer, et al: Does categorisation of lymphoma subtypes according to the World Health Organization classification predict clinical outcome in cats? J Feline Med Surg. 2016 Aug 30 [epub ahead of print, accessed 2/20/19] DOI: 10.1177/1098612X16666119
Blake MK, Carr BJ, Mauldin GE: Hypersensitivity reactions associated with L-asparaginase administration in 142 dogs and 68 cats with lymphoid malignancies: 2007—2012. Can Vet J. 2016 Feb;57(2):176-182. PMCID: PMC4712998
Schmidt S, Nerschbach V, Eberle N, et al: Renal lymphoma in a cat: diagnostics, therapy and survival time. A case report. Tierarztl Prax Ausg K Kleintiere Heimtiere. 2012;40(4):271-7.