The role of adhesion molecules is very important both in the activation of carcinogenesis and in the differentiation of subtypes of breast carcinoma, aiding in diagnosis, prognosis and therapeutic choice in these tumors. Therefore, understanding the functions and interrelationships among these molecules is crucial to the pathologist, who often uses these factors as a resource to differentiate tumors and further classify them according to a molecular point of view. Our goal is to describe the applicability and the difficulties encountered by the pathologist in the diagnosis of breast carcinoma, discussing the most commonly used markers of adhesion in routine analyses.