Squamous Epithelial Cells 6-10 in Urine: Clinical Significance
The presence of 6-10 squamous epithelial cells per low-power field in urine typically indicates mild contamination from the distal urethra or external genitalia, but does NOT reliably predict bacterial contamination or invalidate the specimen. 1, 2
Origin and Normal Presence
- Squamous epithelial cells normally originate from the distal urethra, bladder trigone, or in women, from the cervicovaginal region during collection 1, 2
- The distal third of the urethra is lined by squamous epithelium, making their presence in urine a common and often benign finding 1
Impact on Specimen Quality
Your specimen with 6-10 squamous cells is generally acceptable for interpretation, though context matters:
- Research demonstrates that squamous cells are poor predictors of bacterial contamination—in one study, 94% of catheterized samples (the gold standard) contained squamous cells yet had zero bacterial contamination 3
- The traditional teaching that squamous cells indicate contamination is not well-supported by evidence 3, 4
- However, if >10 WBCs are present alongside significant squamous cells, consider potential contamination 1, 2
When to Be Concerned
Recollection is warranted only in specific circumstances:
- If mixed bacterial flora is present alongside squamous cells AND clinical suspicion for UTI remains high, consider recollection using catheterization 1, 2
- Squamous cells >8 per low-power field may reduce the predictive accuracy of urinalysis for bacteriuria (sensitivity/specificity drops from 75%/84% to 86%/70%) 4
- For respiratory specimens (sputum), <25 squamous cells per high-power field is the quality threshold 5, but this standard does not apply to urine
Collection Method Considerations
If repeat collection is needed, use the most reliable method:
- Clean-catch specimens have 27% contamination rates 1, 2
- Catheterized specimens have only 4.7% contamination rates with 95% sensitivity and 99% specificity 1, 2
- Proper perineal cleansing before collection reduces contamination from 23.9% to 7.8% 1, 2
Rare Malignancy Considerations
While uncommon (0.3% incidence), atypical squamous cells warrant attention:
- Atypical squamous cells in urine may indicate squamous cell carcinoma of the bladder, urothelial carcinoma with squamous differentiation, or cervical malignancy 6, 7
- In one series, 31% of patients with atypical squamous cells were later diagnosed with malignancy 7
- Your finding of 6-10 normal-appearing squamous cells does not fall into this category and requires no special follow-up 1, 2