Which cell type would be part of the urine microscopy pattern in a patient who had a catheter inserted and then removed from the urethra and bladder?

Which cell type would be part of the urine microscopy pattern in a patient who had a catheter inserted and then removed from the urethra and bladder?

• A. Squamous epithelial cells
• B. Transitional epithelial cells
• C. Renal epithelial cells
• D. Ammonium biurate crystals

Answer: (B)

Urine sediment cell types reflect the tissues lining the urinary tract. The bladder and parts of the renal pelvis and ureters are lined by transitional epithelium (urothelium). Inserting and then removing a catheter irritates this mucosa, causing shedding of transitional epithelial cells into the urine. Squamous epithelial cells come from the distal urethra or external genitalia and are more likely to appear as contaminants from sampling, not as a response to bladder instrumentation. Renal epithelial cells would indicate tubular injury, which isn’t the typical pattern produced by catheterization alone. Ammonium biurate crystals are crystals, not cells, and don’t describe the observed sediment pattern. So transitional epithelial cells best explain the urine microscopy after catheter manipulation.

Urine sediment cell types reflect the tissues lining the urinary tract. The bladder and parts of the renal pelvis and ureters are lined by transitional epithelium (urothelium). Inserting and then removing a catheter irritates this mucosa, causing shedding of transitional epithelial cells into the urine. Squamous epithelial cells come from the distal urethra or external genitalia and are more likely to appear as contaminants from sampling, not as a response to bladder instrumentation. Renal epithelial cells would indicate tubular injury, which isn’t the typical pattern produced by catheterization alone. Ammonium biurate crystals are crystals, not cells, and don’t describe the observed sediment pattern. So transitional epithelial cells best explain the urine microscopy after catheter manipulation.