What is the appearance of casts?

• A. Cylindrical with parallel sides
• B. Round and irregular
• C. Flattened and thin
• D. Pliant and flexible

Answer: (A)

The appearance of casts in urine is characterized as cylindrical with parallel sides. This specific shape arises from the molding of the casts within the renal tubules where they are formed. The casts may vary in composition, such as hyaline, granular, or cellular, but their defining feature remains the cylindrical form. This structure allows them to maintain a consistent shape as they pass through the urinary tract. Understanding this characteristic is essential for interpreting urine sediment examinations and can provide valuable insights into renal pathology. This adherence to a cylindrical shape helps in differentiating casts from other urinary sediment components, which may display a variety of forms and shapes.