Case Study

Renal mass in a 16 year old FS DSH cat

A 16-year-old spayed female DSH cat was presented for evaluation of inappropriate urination. Urinalysis showed inappropriate SG (1.015) and hematuria with culture being negative. Abnormalities on CBC and serum biochemistry included mild microcytic-hypochromic anemia, mild hypoproteinemia, and mild azotemia.

Sonographic Differential Diagnosis

There is an expansive left renal mass. Carcinoma or other neoplasia is suspected. The right kidney is unremarkable. There was no overt evidence of metastatic disease. The renal mass appears to be encapsulated.

Image Interpretation

The renal architecture in this patient presented ill-defined corticomedullary definition with nebulous hyperechoic cortices exemplary of fibrosis and chronic inflammatory lesions. Focal areas of dystrophic mineralization were evident without overt hydronephrosis. The right kidney presented dystrophic mineralization. The left kidney comprised a mass with mixed, hypoechoic expansive nodular changes. Pericapsular inflammatory pattern and areas of mineralization were noted. FNA or left nephrectomy would be recommended.

DX

Renal mass

Outcome

None

Comments

Chest radiographs and exploratory surgery with expectations towards left nephrectomy would be recommended. Direct inspection of the liver during surgery would be recommended as well.

Clinical Differential Diagnosis

Bladder disease: urolith, neoplasia, granulomatous cystitis, polyploid cystitis; Renal disease: chronic kidney disease, neoplasia, renolith, pyelonephritis.