Epithelial cells line the urinary tract from the kidneys to the urethra. A small number of squamous epithelial cells (from the urethra or external genitalia) in urine are normal. The presence of transitional epithelial cells (from the bladder or ureters) or renal tubular epithelial cells (from the kidney tubules) in significant numbers is more clinically significant.
Large numbers of squamous epithelial cells usually indicate sample contamination. Transitional epithelial cells in clusters can suggest bladder irritation, infection, or — in some contexts — bladder cancer. Renal tubular cells suggest kidney tubular injury. Epithelial cell count is assessed as part of urine microscopy and helps the clinician interpret other microscopy findings in context.
FAQs
What does it mean if my urine has many squamous epithelial cells?
Large numbers of squamous cells almost always indicate sample contamination from the perineum, vagina, or foreskin. The test should be repeated with improved clean-catch technique before treating for UTI based on other dipstick findings.
Are renal tubular cells serious?
Yes. Their presence in significant numbers indicates kidney tubular injury (acute tubular necrosis). Causes include ischaemia, nephrotoxic drugs, contrast agents, and sepsis. Urgent assessment of kidney function is needed.
What are transitional epithelial cell clusters?
Clusters of transitional cells in urine may indicate significant bladder irritation or, in the appropriate clinical context, possible urothelial malignancy. They warrant further investigation including cystoscopy.
Does urinary instrumentation affect epithelial cell counts?
Yes. Catheterisation, cystoscopy, and other procedures displace epithelial cells into the urine, raising counts that are expected and not clinically significant in this context.
