Journal of Research in Medical Sciences1735-199513520081019Mast cells in invasive ductal breast carcinoma255259ENMitraHeidarpourDepartment of Pathology, Isfahan University of Medical Sciences, Isfahan.. heidarpour@med.mui.ac.irMohammad AliRajabiParvinRajabiHossein SafarAliFarkhani2008011720080706BACKGROUND: Inflammatory cells in the tumor stroma have gained increasing interests recently. We aimed to study the prognostic impact of the presence of stromal mast cells in invasive breast carcinomas. METHODS: Tissue sections of 108 cases with invasive breast cancers were prepared and stained with Giemsa. The presence of stromal mast cells were evaluated and its correlation with tumor’s grade, tumor size, positivity for estrogen and progesterone receptors (ER and PR, respectively), HER2/neu positivity and lymph node metastasis was analysed. RESULTS: The median age was 52.3 years (range 28-85 years). Grading was done according to the Nottingham Modification of the Bloom-Richardson system. Fifty-four (50%) women had grade 1, 16 (14.8%) had grade 2 and 38 (35.2%) had grade 3 tumor. The presence of stromal mast cells correlated significantly to low grade tumors (p = 0.004) and ER Positivity (p = 0.04). There was no correlation between the presence of stromal mast cells and the PR positivity, HER2/neu positivity, tumor size and lymph node metastasis (p > 0.05). CONCLUSIONS: Our results indicated that the presence of mast cells in breast cancer is correlated with a much lower grade of this tumor. Also in our study, there was a positive correlation between ER receptor positivity and the presence of mast cells in the stroma of breast cancer. KEY WORDS: Invasive ductal carcinoma, mast cell, prognosis.