Computerized Cytomorphometric and Cytomorphological Analysis of Canine Transmissible Venereal Tumours

Canine transmissible venereal tumour (CTVT) has three cytomorphological types: plasmacytic, lymphocytic and mixed type. Cytomorphometry, a method of computerized image analysis, has been used recently in veterinary medicine. This study compared the nuclear and cellular morphometric parameters (i.e. radius, diameter, perimeter and area) in different types of CTVT with other canine round cell tumours including lymphoma, mast cell tumour (MCT) and histiocytic tumour (HCT). We also evaluated the relationship between clinical information and the different CTVT cytomorphologic types. CTVT cells from 44 dogs revealed that the measured parameters were significantly different between different round cell tumours and among the CTVT cytomorphological types. CTVT had the largest cells, followed by HCTs, MCTs and lymphomas. The mixed type of CTVT had the largest nuclear and cellular size, followed by the plasmacytic and lymphocytic types. Lymphocytic CTVTs had less aggressive biological behaviour than the other types. Mixed type CTVTs were more likely to show malignant behaviour including metastasis and resistance to chemotherapy; however, there was no significant correlation between cytomorphological type of CTVT and response to chemotherapy.