May Be Caused by

 Common

Abscess

Acute focal bacterial nephritis

Autosomal dominant polycystic kidney disease

Focal hydronephrosis

Hydatid cyst

Necrotic neoplasm

Renal abscess

Renal cyst

 Uncommon

Aneurysm

Arteriovenous fistulas

Calyceal diverticulum

Cystic hematoma

Infection with necrosis

Multicystic dysplastic kidney

Multilocular cystic nephroma

Multilocular renal cyst

Pseudoaneurysm

Tuberculosis

Urinoma