OBSTRUCTIVE DISORDERS OF THE URINARY SYSTEM
Hydronephrosis is a common complication of urinary tract obstruction. It is char-acterized by dilation of the ureter and renal pelvis. Specific causes include renal stones, retroperitoneal fibrosis, benign prostatic hyperplasia, and cervical cancer.
• In unilateral hydronephrosis, the kidney may enlarge to 20 cm. It may be found incidentally on physical exam. The parenchyma becomes compressed. If complete obstruction occurs suddenly, necrosis of the renal papillae may result.
• Bilateral obstruction that is complete presents as anuria; incomplete bilateral obstruction may present as polyuria.