Introduction: Breast cancer is the most frequent malignant tumor of women worldwide, with increasing incidence rates . The assessment of prognostic factors, in order to provide a prediction of outcome, has become an essential part of the histopathologist’s role in the handling and histological reporting of invasive breast carcinomasThe role of the immune system during cancer development is complex involving extensive reciprocal interactions between genetically altered cells, immune cells, and the neoplastic microenvironment .Studies on the role of mast cells in cancer have given contrasting results, research on breast cancer was specifically of importance, because some aspects of its carcinogenesis, such as the diversity of the hormonal component, differ greatly Material & methods: Fifty cases of breast cancer were collected randomly as tissue sections and cell block prepared material. The cases were stained by Haematoxylin and Eosin, ckit (CD 117) immunostaining and toluidine blue special stain for mast cells detection followed by their quantitative evaluation.Results: The majority of cases presented in the age group 41-50 years representing (36%) of the total count of cases. This study revealed that the most common type was invasive duct carcinoma NOS representing (84% )of the cases. .Most were those with maximal dimension were within the range between 2cm up to less than 5 cm compromising (68%) of cases, the majority of cases the majority of cases (62 %), showed positive nodal status. No statistical correlation was found between mast cells and clinicopathological factors of breast cancer. On the other hand, there was significant correlation between nuclear grade and ckit (CD117) expression.