Case Study

Cystic renal mass in a 13 year old FS DSH cat

A 13-year-old spayed female DSH cat was presented for evaluation of a large abdominal mass. Abnormalities on CBC and serum biochemistry were leukocytosis, neutrophilia, monocytosis, thrombocytosis, anemia, and elevated urea. Total T4 and PT/PTT were normal.

Sonographic Differential Diagnosis

Cystic renal mass deriving from the caudal pole of the right kidney. Infarction in the left kidney. No obvious metastatic disease. Exploratory surgery would be recommended if chest radiographs are normal.

Image Interpretation

The left kidney presented a caudal infarction. No obvious neoplasia was noted. The right kidney comprised a 12+ cm cystic parenchymal mass that measured 4.0 cm at the caudal pole of the residual kidney. Multiple large cysts were noted. This is most consistent with cystic adenocarcinoma with the possibility of complicating polycystic kidney disease. About 70% of the kidney itself was fluid filled. No obvious metastatic disease was noted.

DX

Cystic renal mass

Outcome

Exploratory surgery was performed and the patient was euthanized.

Clinical Differential Diagnosis

Abdominal mass – neoplasia, granuloma, cyst or abscess of any of the organs, hydronephrosis, gastric obstruction or neoplasia, intra-abdominal neoplasia.