Answer:

Sonographic findings: Cystic mass with thick tissue rim and central tissue portion in caudal pole of right kidney. Hypoechoic nodule in liver.

Diagnosis: Renal carcinoma was diagnosed in both locations. Renal carcinoma may be in both kidneys, either as a metastasis to the contralateral kidney or bilateral spontaneous primary masses. Metastases are uncommon and a benign cause of the liver nodule should be considered. Fine needle aspiration confirmed a carcinoma diagnosis in the liver nodule.