A medical student examines the centrifuged urine of a patient with hematuria. The sediment shows red blood cell casts and dysmorphic erythrocytes with blebs and irregular shapes. This finding localizes the source of bleeding to which site?

• A Bladder
• B Renal pelvis and ureter
• C Prostatic urethra
• D Glomerulus ✓

Explanation

Dysmorphic red cells and red blood cell casts arise when erythrocytes cross a damaged glomerular filtration barrier and are deformed by passage through tubules, where casts are molded. Lower urinary tract bleeding from bladder, ureter, or prostate yields isomorphic red cells without casts. Recognizing a nephritic urinary sediment is the bedside clue that separates glomerular disease from urological causes of hematuria.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.