Name six lesions that can mimic renal cysts on ultrasound.

Hypoechoic structures:
1. Renal pyramids
2. Urine collections (e.g., urinoma or localized hydronephrosis)
3. Abscesses
4. Hematomas
5. Intrarenal vascular malformations
6. Lymphoma
all can mimic renal cysts on ultrasound.