A systematic approach to identifying urothelial cells likely to be polysomic by fluorescence in situ hybridization

OBJECTIVE: To determine which nuclear morphologic and background features are most associated with normal and abnormal chromosome patterns in urine cells evaluated by fluorescence in situ hybridization (FISH) with Vysis® UroVysion (Downers Grove, Illinois, U.S.A.). STUDY DESIGN: One hundred specimens were analyzed and the nuclear morphologic and background features compared between FISH-negative (disomic) and -positive (polysomic) cases. RESULTS: Our data show that polysomic urothelial cells have significantly (p < 0.001) weaker DAPI nuclear counterstaining, nuclear enlargement, more irregular nuclear shape and more chromatin clumping when compared to disomic cells. CONCLUSION: These findings indicate that there are specific staining and nuclear cytologic features that can help identify cells that have a high probability of being polysomic by FISH. This information may help cytologists decrease the time required to evaluate urine specimens by FISH and may aid in the development of instruments that automate FISH analysis.