Case summaryA 10-year-old spayed female American Shorthair cat underwent renal
transplantation due to worsening chronic kidney disease secondary to
polycystic kidney disease. During transplantation, the right kidney grossly
appeared to be more diseased than the left and was firmly adhered to the
surrounding tissues. An intraoperative fine-needle aspirate of the right
native kidney revealed inflammatory cells but no evidence of neoplasia. To
create space for the allograft, a right nephrectomy was performed. Following
nephrectomy, the right native kidney was submitted for biopsy. Biopsy
results revealed a renal cell carcinoma. Although the cat initially
recovered well from surgery, delayed graft function was a concern in the
early postoperative period. Significant azotemia persisted and the cat began
to have diarrhea. Erythematous skin lesions developed in the perineal and
inguinal regions, which were suspected to be secondary to thromboembolic
disease based on histopathology. The cat’s clinical status continued to
decline with development of signs of sepsis, followed by marked obtundation
with uncontrollable seizures. Given the postoperative diagnosis of renal
cell carcinoma and the cat’s progressively declining clinical status, humane
euthanasia was elected.Relevance and novel informationThis case is the first to document renal cell carcinoma in a cat with
polycystic kidney disease. An association of the two diseases has been
reported in the human literature, but such a link has yet to be described in
veterinary medicine. Given the association reported in the human literature,
a plausible relationship between polycystic kidney disease and renal cell
carcinoma in cats merits further investigation.