EN
The aim of the study was to determine the level of vascularization of neoplastic and healthy splenic parenchyma tissue in dogs. The first research group comprised spleen samples with diagnosed tumor changes extracted during splenectomy. Four male and five female dogs, aged between 8 and 13 years and of various races, were operated on. The second group comprised 10 samples of healthy spleen tissue extracted post-mortem. After staining with haematoxylin and eosin, the samples were diagnosed and the tumor type classified according to the official WHO classification. In order to render the vascular endothelium visible, immunohistochemical staining was performed with the use of the polyclonal antibody against the von Willebrand factor F VIII and the DAKO EnVision system. Angiogenesis that was observed in malignant spleen cancer tissue was intensified in comparison to that in healthy perenchyma tissue. The mean vascular density observed in malignant splenic tumors was 87 capillary vessels/mm². The mean vessel density was 60/mm² in lymphomas, while in angiosarcomas it averaged 108/mm². In healthy splenic tissue the observed mean vascular density was 14 vessels/mm². The highest vascular density was noted in tumors with metastases to other abdominal cavity organs (mean - 132 vessels/mm²). The observations may provide practitioners with a valuable prognostic insight into the potential danger of metastasis.