A Modified Direct-Smear Processing Technique Employing Two-Step Centrifugation/Fixation Is Useful for Detecting High-Grade Urothelial Carcinoma

To demonstrate the usefulness of a direct-smear processing technique employing two-step centrifugation/fixation processing (TSCFP) in the cytoscreening of high-grade urothelial carcinoma (HGUC).

Using the T24 HGUC cell line, we compared the cell yield and the morphological preservation of preparations concurrently processed by direct-smear, SurePath, ThinPrep, and TSCFP techniques. A total of 287 urine cytology cases subjected to TSCFP over a period of 6 years were reviewed and reclassified according to the Paris System for Reporting Urinary Cytology (PSRUC) and correlated with histology results.

TSCFP of T24 cells demonstrated good cell yield with a recovery rate of about 70%. Diagnostic features of HGUC, such as a high nuclear/cytoplasmic ratio and irregular/hyperchromatic chromatin, were better discovered in TSCFP smears than in smears prepared with the other methods. Cytological evaluation of 287 voided urine specimens revealed that the rate of unsatisfactory preparations was quite low (0.30%) and the overall sensitivity, specificity, and positive and negative predictive values for urothelial carcinoma were 0.719, 0.923, 0.973, and 0.462, respectively.

TSCFP was able to provide adequate preparations for detecting HGUC in urine cytology and could be considered as a promising processing method according to the principal purpose of PSRUC.

Acta cytologica. 2017 Sep 28 [Epub ahead of print]

Yasuhiro Toyonaga, Kazuto Yamazaki, Yoshinori Koyama, Masatoshi Yamada, Yasuo Ishida