A 65-year-old female patient with an infected cyst (R24 in Fig 2).

(A) Pre-contrast CT image shows a 9.7 cm sized round cyst that has higher attenuation than the surrounding cysts in right kidney upper pole (arrow). (B, C) On the arterial and portal venous phase images, the cyst shows discernible wall thickening with prominent wall enhancement and pericystic fat infiltration (arrows).