EVALUATION OF BRUSH CYTOLOGY IN THE DIAGNOSIS OF CHRONIC INTRANASAL DISEASE IN CATS

Brush cytology was used as a diagnostic aid in 85 cats affected with c hronic intranasal disease. Fifty-three of these cases, sampled over a five-year period, were included in this study, while the other cases w ere excluded due to poor cellularity of the cytological samples (nine cases) or a lack of histological or follow-up data (23 cases). Thirty- six brush samples were classified by cytology as inflammatory. Subsequ ent histological examination revealed a false negative diagnosis of ne oplasia in six cats, two of which had malignant tumours (one adenocarc inoma and one lymphoma), the remaining four having benign tumours (two adenomas and two osteochondromas). Seventeen samples were classified by brush cytology as neoplastic. This was confirmed in 16 of these cas es by histology or follow-up (nine epithelial malignant tumours, six l ymphomas and one osteosarcoma). In the remaining case, a false positiv e diagnosis of lymphoma was made, The procedure had an overall 86.8 pe r cent (46/53) agreement between the diagnosis of inflammatory conditi ons versus neoplasia, with a sensitivity of 72.7 per cent, a specifici ty of 96.8 per cent, a predictive value of a positive test of 94.1 per cent and a predictive value of a negative test of 83.3 per cent.