Anechoic renal mass

Echo-free renal mass

Common: Autosomal dominant polycystic kidney disease; Focal hydronephrosis; Hydatid cyst; Lymphoma; Necrotic renal cell carcinoma; Perirenal abscess; Renal abscess; Renal cyst; Renal cyst with small mural tumor; Renal neoplasm
Uncommon: Aneurysm of renal artery; Arteriovenous malformation; Caliectasis; Calyceal diverticulum; Duplication with ectopic ureterocele; Hemorrhage; Lymphocele; Medullary cystic kidney disease; Multicystic dysplastic kidney; Pyonephrosis; Seroma; Tuberculous cavity; Urinoma