Sandbox: DDx Kidney mass

• Male patients on dialysis
• Asymptomatic
• May have hematuria with flank pain if ruptured
• No family history of cystic diseases

• Bilateral renal development of small fluid-filled cysts
• Kidneys are typically small in size
• Involve both the cortex and medulla
• Cystic hemorrhage and calcification

• Cysts surrounded by normal renal parenchyma or interstitial fibrosis
• Surrounded by a single layer of cuboidal epithelial cells or multilayered epithelial lining
• Oxalate crystal deposition

Nonmalignant causes

acquired cystic kidney disease  cystic renal dysplasia glomerulocystic kidney  mesothelial cysts nephronophthisis