Abstract: Canine mast cell tumors account for up to 20% of all skin tumors in dogs. While they often appear small and somewhat insignificant, they can be a very serious form of cancer in the dog. Some mast cell tumors are easily removed without the development of any further problems and others can lead to a life threatening disease. Proper identification and treatment are very important in controlling these tumors. The final diagnosis "mast cell tumor" of a case of canine cutaneous lump was based on the demonstration of focal accumulations of mast cells with typical histological and cytomorphological properties via hematoxylin eosin staining,Toluidine Blue staining of the paraffin sections.

Key words: mast cell tumor; histopathology; canine; skin