Approximately how many hyaline casts per low-power field were reported in the described sediment?

• A. 0-3
• B. 10-20
• C. 5-9
• D. 25-30

Answer: (B)

Hyaline casts are the simplest and most common type of cast in urine, formed mainly from Tamm-Horsfall protein secreted in the tubules. They are colorless and transparent and can be seen even in normal urine, but their numbers rise when urine flow is reduced or the urine is concentrated, such as with dehydration or mild tubular stress.

If the described sediment shows about 10–20 hyaline casts per low-power field, that indicates a moderate level of cast formation. This density is higher than what you'd expect in fully normal urine (which would be few or none) and is consistent with conditions that concentrate urine or mildly irritate the tubules.

Smaller counts (0–3 or 5–9 per LPF) would suggest only minimal or no abnormal cast formation, while a very high count (25–30 per LPF) would imply a more severe process. The reported range of 10–20 per LPF best fits a sediment described as having a noticeable but not extreme number of hyaline casts.