Extraglomerular (non-glomerular) hematuria is characterized by which findings?

• A. Normal RBC morphology, no casts or proteinuria
• B. RBC casts present
• C. Dysmorphic RBCs
• D. Proteinuria present

Answer: (A)

The main idea is that bleeding outside the glomerulus leaves red cells in the urine largely intact and without signs of glomerular injury. Extraglomerular (non-glomerular) hematuria typically shows normal red blood cell morphology, because the cells haven’t undergone the damage that occurs during filtration. There are usually no red blood cell casts, since the bleeding source isn’t within the tubules, and proteinuria is not increased because the glomerular filtration barrier isn’t disrupted. In contrast, glomerular bleeding often produces dysmorphic red cells, red cell casts, and proteinuria due to glomerular injury.