In a urine sediment where hyaline casts and mucus are present with normal chemical results, what is the most likely interpretation?

• A. Nephrotic syndrome
• B. Normal sediment
• C. Glomerulonephritis
• D. Pyelonephritis

Answer: (B)

Hyaline casts are the most common and are often seen in normal urine. They form from Tamm-Horsfall protein and are nonspecific, sometimes appearing with concentrated urine, mild dehydration, or recent exercise. Mucus can also be present in normal urine and does not indicate disease. When the urine chemical screen is normal—no protein, blood, leukocytes, nitrites, or other abnormal findings—the sediment pattern fits a nonpathologic state. In nephrotic syndrome, you'd expect heavy proteinuria and lipid/protein casts; in glomerulonephritis, there would be red blood cell or dysmorphic RBCs and possibly RBC casts; in pyelonephritis, you'd typically see white blood cells or bacteria and WBC casts. So the combination of hyaline casts with normal chemistry points to a normal urine sediment.