Studies on histogenesis of mixed tumours of the mammary gland in bitches.

The aim of the study was the immunohistochemical assessment of the reactivity of mixed tumours in bitches with special regard to myoepithelial cells and cartilage. The materials for study were 20 mixed tumours collected during surgery or autopsy. Paraffin-embedded sections were routinely stained with hematoxylin and eosin and HID method was also used. Immunohistochemical assays were made using the AB-Complex method with the use of monoclonal antibodies against: cytokeratin MNF-116, cytokeratin 19, vimentin, actin and S-100 protein. On the basis of the reactions, 5 types of myoepithelial origin cells transformed during the formation of cartilage cells were diagnosed.