Expression of vimentin and high-molecular-weight cytokeratin (clone 34ßE12) in differentiating reactive renal tubular cells from low-grade urothelial carcinoma cells in voided urine.

OBJECTIVE

Reactive renal tubular cells show features of an atypical repair reaction. Differentiation between reactive renal tubular cells and low-grade urothelial carcinoma (LG-UC) cells can therefore be a diagnostic challenge based on morphology alone. In this study, we evaluated the diagnostic utility of vimentin and a high-molecular-weight cytokeratin antibody (clone 34ßE12) in differentiating reactive renal tubular cells from LG-UC.

METHODS

We evaluated voided urine cytology and surgical specimens from 40 patients with renal disease, and 17 patients with LG-UC. All slides were stained with vimentin and 34ßE12.

RESULTS

In the reactive renal tubular cells in voided urine cytology, vimentin showed strong cytoplasmic staining in 39/40 (97.5%) cases, but all were negative for 34ßE12. LG-UC cells showed positive staining for 34ßE12 in 3/17 (17.6%) cases, whereas none were positivity for vimentin. The reactive renal tubular cells of histological specimens in the renal disease group demonstrated positive for vimentin in all 40 cases and all were negative for 34ßE12. The LG-UC group showed abnormal staining for 34ßE12 in 4/17 (23.5%) cases, whereas none were positive for vimentin.

CONCLUSIONS

Vimentin expression in urine cytology can help to distinguish reactive renal tubular cells from LG-UC. However, 34ßE12 does not appear to be a useful adjunct to distinguish these two groups in voided urine cytology.