What are the next steps for a patient with a urine cytology report showing scattered 3-dimensional clusters of urothelial cells with mildly increased nuclear cytoplasmic ratios, reactive changes, mixed inflammation, and bacterial elements?

Interpretation of Urine Cytology Report and Recommended Next Steps

The urine cytology findings suggest a reactive/inflammatory process with possible papillary lesion that requires follow-up cystoscopy and treatment of the underlying infection. 1

Understanding the Cytology Report

• The report describes "scattered 3-dimensional clusters of urothelial cells with mildly increased nuclear cytoplasmic ratios" in a background of reactive changes, inflammation, and bacterial elements, which is consistent with an inflammatory or infectious process rather than a high-grade neoplasm 1, 2
• The absence of "cytologic features of a high-grade urothelial neoplasm" is reassuring, as high-grade urothelial carcinoma typically shows more severe nuclear abnormalities 3
• The report specifically mentions potential diagnostic considerations including:
  • Infection/inflammation (supported by the presence of bacterial elements)
  • Lithiasis (stone disease)
  • Recent instrumentation
  • Papillary lesions 1, 2

Recommended Management Algorithm

1. Treat the underlying infection first

   • Initiate appropriate antibiotic therapy based on urine culture and sensitivity results 4
   • Complete the full course of antibiotics to ensure complete resolution of infection 4

2. Schedule follow-up cystoscopy

   • Cystoscopy remains the gold standard for evaluation of potential papillary lesions mentioned in the report 5
   • This should be performed after resolution of the infection to minimize inflammation that could interfere with visualization 4

3. Consider repeat urine cytology

   • After treatment of infection, obtain repeat urine cytology to determine if the cellular changes persist 2
   • Persistent cellular atypia after treatment of infection would increase concern for a neoplastic process 2

4. Additional imaging if indicated

   • If lithiasis was mentioned as a consideration, appropriate imaging (ultrasound or CT) may be warranted 4

Clinical Significance and Interpretation

• The finding of 3-dimensional clusters with mildly increased nuclear-to-cytoplasmic ratios falls into the "atypical" category in most cytology classification systems 2
• Studies show that approximately 68% of "atypical" urine cytology findings have a positive histologic diagnosis of urothelial malignancy on follow-up 2
• However, the presence of inflammation and bacterial elements in this case suggests that these changes are more likely reactive rather than neoplastic 1, 2

Important Considerations

• Reactive changes due to inflammation can mimic low-grade papillary neoplasms, making definitive cytologic diagnosis challenging 6
• The Paris System for Reporting Urinary Cytology recommends standardized terminology for urine cytology interpretation, with "atypical urothelial cells" being a category that includes many cases of low-grade urothelial carcinoma 1
• The absence of high-grade features is important, as high-grade urothelial carcinoma has a much higher risk of progression and requires more aggressive management 7

Pitfalls to Avoid

• Do not dismiss the finding of 3-dimensional clusters as purely inflammatory without appropriate follow-up, as this could miss an underlying papillary lesion 2
• Avoid performing cystoscopy while active infection is present, as inflammation can make interpretation difficult 4
• Do not rely solely on cytology for diagnosis, as its sensitivity for detecting low-grade urothelial neoplasms is limited (25-37%) 6