Cytologic features of urothelial carcinoma in catheterized urine with cellular fragments.

OBJECTIVE

To identify architectural and cytomorphologic differences that might help distinguish urothelial neoplasms from instrumentation artifact.

STUDY

DESIGN

We examined 73 cytologic smears of catheterized urine containing urothelial cell clusters between 1998 and 2004. All patients had at least 1 follow-up biopsy. Smears were reviewed for several morphologic features blindly, without knowledge of the follow-up diagnosis.

RESULTS

Of the 73 smears, 39 had a benign diagnosis on follow-up biopsy, and 34 had urothelial carcinoma. Cytoplasmic collar, regular and rounded fragment borders, and fine nuclear chromatin were statistically more common in benign smears than those with urothelial carcinoma (p < 0.0001). No significant differences were identified with regard to the presence of background inflammation or nucleoli in the urine specimens. Of the 17 smears that had a cytoplasmic collar, regular fragment borders and fine nuclear chromatin, only 1 (6%) was found to have urothelial carcinoma on follow-up biopsy. All 20 smears in which all 3 features were absent were proven malignant on biopsy.

CONCLUSION

Certain architectural and nuclear features can help differentiate urothelial neoplasms from instrumentation artifact in urine cytologic smears.