EN
The aim of the study was the evaluation of the degree of tumor vascularization in dogs. The examinations were performed on 42 tumors, taken surgically from dogs affected with skin and subcutaneous tissue tumors. Twenty three male and nineteen female mixed breed dogs aged 3 to 15 years were operated. The dogs had not been treated for neoplasma diseases earlier. The tumor samples were fixed in 10% buffered formalin for 24 hours, after which the tissues were dehydrated in increasing concentrations of alcohol and embedded in paraffin. The slides were stained with hematoxyline and eosine. The tumor type was determined according to the current WHO classification. For the endothelium vessel observations immunohistochemical staining was performed with the use of polyclonal antibody directed against the von Willebrand factor (FVIII). The estimation of blood vessel quantity was performed in a microscope equipped with a computer image analysis system. The itratumoral microvessel density was calculated in 10 selected areas. The average of microvessel density was 190 per 1 mm² in malignant tumors and 138/mm˛ in benign tumors. It was found that the degree of malignant tumor vascularization was much larger than that of the benign tumor. Tumor angiogenesis determination can be used for diagnosis, prognosis, as well as for the degree of malignancy classification and metastatic potential.