Spontaneous skin canine tumors: toluidine blue stain detection of mast cells in tissue section.

Dog mast cell tumor (MCT) is common in dog. The etiology of canine MCTs is unknown, but it is probably multi-factorial. Its incidence is higher than it has found in human. There are demonstrated several common biological and clinical characteristics in both species. Cutaneous mast cells are located in the dermis and hypodermis. The objective of this study is to detect of MC on Toluidine Blue stained slides. There were examined 74 dogs of difference breeds and aged, from Tirana city. Six of them demonstrated the skin canine tumors. Skin samples were obtained from these animals. Macroscopic examination of the tumor revealed nodular ulcerated lesion with areas of necrosis and hemorrhage, accompanied with normal superjacent epidermis and annexes. Serial sections obtained from biopsy specimens were processed with toluidine blue staining pH 4.5, specific for MC identification. This study suggests that Toluidine blue, pH 4.5 stain may give a good information about skin tumors in dog, histologically with benign behavior.