Comparison of histologic and cytologic specimens of urothelial carcinoma with image analysis. Implications for grading.

Objective: To compare DNA results obtained by each of three preparation types (cytologic smears or cytocentrifuge samples, tissue sections and nuclei extracted from paraffin-embedded tissue) on patients with primary urothelial cell carcinoma of the bladder.

Study Design: Cases were selected for study based on the histologic diagnosis and the availability of corresponding bladder washing cytologic specimens. Five-micrometer sections and nuclear extracts were prepared from biopsies. DNA analysis was accomplished by use of an image cytometer on the Feulgen-stained material.

Results: DNA content results correlated with both histologic and cytologic grade. Using a binary classification system, bladder washings and thin tissue section results concurred in 40/43 patients. Nuclear extracts were performed on 27 of the biopsies. The DNA content determined by nuclear extract agreed with the tissue section results for all 27 biopsies.

Conclusion: All three specimen preparations yield comparable DNA content results using a binary DNA classification scheme (diploid or aneuploid). Histologic grading can be enhanced with DNA content results, particularly in the heterogeneous, grade 2 group of urothelial carcinomas.