Cytologic evaluation of inflammation in canine liver aspirates.

Liver aspiration cytology has been used routinely for more than a decade for the evaluation of canine and feline liver disease. However, the value of liver cytology in detecting inflammatory liver disease is poorly defined. We retrospectively reviewed 51 canine liver cytology reports and compared the conclusions with those from concurrent surgical biopsy reports. Overall sensitivity of cytology for diagnosis of inflammatory liver disease was 93% and specificity was 96%. For suppurative hepatitis (n = 14), the sensitivity of cytologic diagnosis was 100% and the specificity was 95%. For chronic active hepatitis (n = 13), the sensitivity of cytologic diagnosis was 100% and the specificity was 93%. For lymphocytic hepatitis (n = 3), the sensitivity of cytologic diagnosis was 33% and the specificity was 100%. We conclude that canine liver aspiration cytology is a highly sensitive test for the detection of suppurative and chronic active inflammation; however, it is insensitive for the detection of lymphocytic hepatitis.