Atypical urothelial cells (AUC): A Bethesda-derived wording applicable to urinary cytopathology

Aims. - To investigate (1) whether sparse nuclear atypias involving deep urothelial cells have a diagnostic or prognostic value in urinary cytology, and (2) whether the terms atypical urothelial cells of undetermined significance (AUC-US) or cannot exclude high grade (AUC-H) might be used to standardize urinary cytology reports. Patients and methods. - Atypical urothelial cells (AUC) were defined as deep cells with nuclear abnormalities (increased N/C ratio, eccentric nucleus, hyperchromatism and/or irregular shape) in small number not allowing their categorization as malignant, high grade. We studied 435 urinary samples from 126 patients with AUC at any step of their clinical history, followed up over a 10-year period (1999-2009). Every case was compared with histopathology within 6 months and to long term follow-up including cystoscopy and histopathology combined. Results. - A total of 183 AUC was recorded. AUC were associated with negative, benign or low grade histological results in 36 of 106 cases (33.9%) within 6 months, but a high grade was simultaneously documented in 70 cases (66 %). AUC preceded high-grade lesions in 66 cases (36.1% of all AUC) in a mean interval of 10.5 +/- 12.0 months. Overall, AUC were associated with or predictive of high-grade lesions in 135 cases (73.8%). Conclusion. - AUC have a diagnostic and prognostic value. Applying the terms AUC-US and AUC-H to urinary cytopathology reports would allow, as for the Bethesda system for cervical or vaginal cytologic diagnoses, better appreciation of the risk of progression to high grade tumours in cases with atypias. (C) 2010 Elsevier Masson SAS. All rights reserved.