During the past two decades, mammography has become established as an indispensible addition to complete evaluation of symptomatic women and as a valuable screening method to detect early breast cancer in asymptomatic women. Mammographic microcalcification is a feature in a proportion of breast-cancer patients. So we evaluate the association of mammographic microcalcifications with age, tumor stage, tumor size, axillary lymph-node positivity, estrogen-receptor' progesterone-receptor positivity, histology, nuclear grading, and an extensive intraductal component (EIC). The authors retrospectively reviewed and analyzed 181 cases of breast cancer which were diagnosed and operated on from January 1994 to December 1996. We divided the subjects into two groups based on the presence of mammographic microcalcification or the absence of mammographic calcification. In this paper, we report the results of our analysis along with a review of the literature. The results are as follows: 1) Five of the 66 patients with mammographic microcalcifications had intraductal carcinomas wheres only one of the 115 patients without mammographic microcalcifications had such a carcinoma. 2) The two groups were comparable as to primary tumor size: 3.09 cm in the group with microcalcifications and 2.68 cm in the group without microcalcifications. In particular, the group with microcalcifications and axillary lymph-node metastasis showed a primary tumor size of 4.17 cm. A high rate of axillary lymph-node metastasis was noted for patients with T3 tumors and mammographic microcalcifications. 3) The two groups were comparable as to cancer stage: stage 0.0%, stage I 17.2%, stage II 55.2% and stage III 27.5% for mammographic mierocalcifieations with mass and stage 0 10.8%, stage I 32.4%, stage II 43.2%, and stage III 13.5% for mammographic microcalcifications only. 4) An EIC was present in 6 of the 29 cases (20.6%) with mammographic microcalcifications with mass and in 5 of the 37 cases (13.5%) with mammograhic microcalcifications only. Breast cancer patients with an EIC have a high incidence of local recurrence and a poor prognosis. We must have strict and powerful, primary and systemic management of patients with mammographic microcalcifications with mass.