What is a common characteristic of granular casts?

Granular casts are primarily characterized by their distinct appearance, which includes having a coarse or fine granular texture. They are often described as brittle and refractile due to the presence of various proteins and cellular debris within the cast structure. This brittleness is a result of the nature of the materials aggregated during the casting process, which can scatter light, leading to their refractile quality when viewed under a microscope.

The appearance of granular casts can indicate a range of underlying conditions, often reflecting kidney damage or disease processes, making their identification important in the assessment of renal function and health. Understanding their characteristics can aid in diagnosing disorders such as acute tubular injury or chronic kidney disease, where these casts may be present in the urine.

In contrast, the other options such as being smooth and clear, tapered at both ends, or soft and pliable do not accurately describe granular casts, which are defined by their specific texture and microstructural qualities.