The Clinicopathologic Correlates of Cellular Atypia in Urinary Cytology of Ileal Neobladders

Objective: Ileal neobladders (INBs) are routinely created in patients following cystectomy for urothelial carcinoma (UC). Patients are screened by urinary cytology for tumor recurrence. However, the diagnosis of urothelial atypia remains a nonstandardized category in INB specimens and has never been studied before. Study Design: The cytopathology archives from the Johns Hopkins Hospital were searched over a period of 19 years for specimens from patients with INB and atypical urine cytology. Follow-up surgical pathology results and clinical data were reviewed. Results: A total of 620 urine specimens were identified from patients with INB, 77 of which (12.4%) were diagnosed as ‘atypical’. Of the 51 patients who were followed up, only 3 developed a concordant local recurrence (5.9% positive predictive value), defined as biopsy-proven recurrence within 1 year of atypical cytology. The recurrent patients had more diagnoses of ‘atypical cells suspicious for carcinoma’ than nonrecurrent patients (66 vs. 11.4%; p > 0.10). Conclusion: A diagnosis of urothelial atypia in patients with INB is made as frequently as in patients with native bladders but with a lower positive predictive value (5.9 vs. 12%) for subsequent histologic diagnosis of UC. This suggests that the diagnosis of urothelial atypia in INB may have less clinical significance than in native bladders.