Predictive Factors of Malignancy in Dogs with Focal Liver Lesions Using Clinical Data and Ultrasonographic Features

A definitive diagnosis of focal liver lesions (FLLs) requires invasive procedures for histopathologic examination. Thus, a simpler noninvasive diagnostic method, such as conventional ultrasonography combined with clinical data, is needed for the prediction of liver malignancy. The objective of this study was to examine the diagnostic accuracy of clinical data and ultrasonographic (US) features to differentiate benign and malignant liver lesions. Medical records and US images from dogs with FLLs that underwent abdominal US and histopathologic examinations following surgery or liver biopsy were retrospectively reviewed. Clinical data, including signalment, clinical signs and laboratory findings, and the US features of liver lesions that could act as predictive factors were assessed using univariate and multivariate analyses to evaluate the associations between predictive factors and liver malignancy. Based on the histopathologic results, 55 dogs with malignant lesions and 28 dogs with benign lesions were included in the study. The results of univariate analysis showed that several US features and platelet count were significantly associated with liver malignancy. Multivariate analysis revealed that the platelet count (thrombocytosis; odds ratio [OR]: 4.13, 95% confidence intervals [CI]: 1.81-9.41), lesion size (4.1 cm or greater; OR: 23.83, 95% CI: 3.74-151.95) and echotexture of FLLs (heterogenous; OR: 8.44; 95% CI: 1.37-51.91) were independent predictors for differentiating benign and malignant liver lesions, suggesting that a combination of clinical data and US findings of FLLs could predict liver malignancy in dogs.