Polycystic kidney disease and renal lymphoma in a cat.

A 2-year-old castrated domestic shorthair cat was determined to have polycystic kidney disease (PKD) and renal lymphoma. History and examination findings consisted of progressive lethargy, asymmetric renomegaly, thick segments of small intestine, and anisocoria. Initial diagnostic tests revealed nonregenerative anemia, mild azotemia, and multiple, round anechoic cysts in both kidneys. Renal cystic fluid contained many mature lymphocytes, and results of biochemical analysis indicated that the fluid was consistent with proximal tubular fluid. Stage-3 lymphoma was diagnosed on the basis of histologic evidence of unresectable lymphoma in multiple abdominal organs. Chemotherapy with vincristine sulfate, cytarabine, cyclophosphamide, and prednisone was unsuccessful. Morphologic association between PKD and lymphoma could not be identified after histologic evaluation of the kidneys.