A 5 year old female spayed mixed breed dog presented to the Cornell University Internal Medicine Service on November 22, 2011 for evaluation of left sided renomegaly. The dog was taken to the regular veterinarian in September 2011 for a routine physical exam at which time renomegaly was detected, a cause was not found prompting a referral to Cornell for further evaluation.
On presentation, the dog was bright, alert and responsive and in good body condition with a body condition score of 5/9. Abdominal palpation revealed that the right kidney was mildly enlarged, and the left kidney palpated firm and significantly enlarged. All other exam findings were unremarkable except for mild/moderate plaque and tartar accumulation on the teeth. An abdominal ultrasound revealed a large cavitated mass associated with the caudal pole of the left kidney. An ultrasound guided fine needle aspirate of the mass revealed neoplastic epithelial cells consistent with carcinoma. Based on these results a ureteronephrectomy was performed. On histopathology, a renal cell carcinoma with metastatic disease to the lymph node was revealed. The dog recovered well with IV fluids and pain management and was discharged the day after surgery.
Primary renal neoplasms are uncommon in dogs, constituting 0.3 – 1.7 % of all neoplasms. Dogs with renal carcinoma usually present with vague, nonspecific signs which can often delay diagnosis allowing for metastasis to the lungs and lymph nodes. Ureteronephrectomy is the treatment of choice with a guarded prognosis.