Evaluation of atypical urine cytology progression to malignancy

BACKGROUND: In urine cytology, the diagnosis of atypia is subjective and clinical management based on these results can be difficult to determine. In this study, the authors determined the percentage of atypical urine diagnoses that progressed to positive cytology or surgical pathology results over an 11-year period. METHODS: In a retrospective review of the authors' institution, 1320 atypical urine cytology diagnoses were identified in specimens from 851 patients obtained from January 2000 through December 2010. All subsequent pathology reports were reviewed to determine which patients developed positive cytology/surgical pathology diagnoses. In total, 4106 cytology and surgical pathology specimen reports were reviewed. RESULTS: At the authors' institution, 1320 of 16,299 of urine cytology specimens (8.1%) were diagnosed as atypical during the 11-year period. Overall, 271 of 1320 initial atypical urine specimens (21%) progressed to positive cytology or surgical pathology results with a mean time to progression of 155 days. Of the cases that progressed to malignancy, 118 were high-grade urothelial carcinoma and 92 were low-grade urothelial carcinoma. CONCLUSIONS: The rate of atypia in urine specimens at this institution was 8.1%. Of the specimen types, atypia was the most common in urinary diversion specimens (16%) and the least common in upper tract cytology (3.8%). When diagnosed as atypical, upper tract specimens had the highest percentage of progression to high-grade carcinoma. Therefore, the authors concluded that the diagnosis of atypia in this specimen group has higher clinical significance and should be managed more aggressively. Cancer (Cancer Cytopathol) 2013;121:387-91.