Introduction

Immunocytochemistry (ICC) is an advanced diagnostic technique used in the field of veterinary cytology. We recently developed a rapid-ICC technique for the detection of cytokeratin and vimentin, which helps to determine whether tumor cells were of epithelial or mesenchymal origin. However, the diagnostic value of this rapid-ICC in neoplastic diseases of dogs and cats is yet to be assessed.

Objective

This study aimed to assess the diagnostic accuracy of the rapid-ICC technique in comparison with standard immunohistochemistry (IHC).

Methods

Air-dried smear samples and formalin-fixed paraffin (FFP) sections were prepared from tumors excised from dogs and cats. Smear samples that were used for rapid ICC were stored at -30°C until use (for a few days to 56 months). The cytokeratin and vimentin signals produced by the smear samples that were processed using the rapid ICC technique were compared with those from FFP sections processed using the standard IHC technique.

Results

All smear samples (n = 34) that were stored for up to 46 months showed clear immunopositive signals for cytokeratin and vimentin with rapid-ICC; however, two samples that were stored for 56 months emitted low signals. In samples that were stored up to 24 months (n = 32), the correlation between rapid-ICC and standard-IHC was 81.3% (13/16) in epithelial tumors, 100% (7/7) in mesenchymal tumors, and 100% (9/9) in round-cell tumors.

Conclusion

The rapid-ICC technique can be used as a diagnostic and research tool for neoplastic diseases in dogs and cats.