CYTOLOGICAL EVALUATION OF SMALL MAMMARY NODULES IN THEBITCH

Mammary tumours are extremely common in the bitch and the diagnosis is generally clinical and confirmed by histopathology of the removed tissues. Small mammary nodules are considered less aggressive or benign, and, in the practice, they are not always removed. This study was aimed to cytologically evaluate 48 small (under 2.5 cm) mammary nodules in 43 bitches. All the cases were also T1N0M0, according to the TNM grading scale. Each nodule was aspirated 1 up to 3 times and the slide was stained with Diff-Quick. Cytological evaluation registered: cellularity, cellular types,inflammatory cells, presence of clusters or aggregates, cellular and nuclear pleomorphism, nucleolar abnormalities, mitoses. Sixty-five per cent of nodules were malignant, the remnant cases were diagnosed as benign, hyperplastic or inflammatory lesions. This result demonstrates that it does not exist a cut off for mammary nodules in the bitch, to distinguish between benign and malignant lesions. Small nodules have always to be aspirated and if the malignancy is confirmed they should be removed. Only benign small nodules may be monitored, taking in account that there is evidence that benign mammary lesions are precancerous in the bitch.