Two Korean women (41 and 23-years of age) presented with painful breast enlargement and redness. The involved breast was confirmed as metastatic signet ring cell carcinoma. Although metastatic signet ring cell carcinoma of the breast shows similar clinical symptoms to inflammatory breast cancer, the difference between the two is that this malignancy showed no microcalcifications or mass on radiographic findings (mammograms and US). Therefore, after the confirmation of signet ring cell carcinoma of the breast has been made, metastatic signet ring cell carcinoma should be considered if there are no microcalcifications or masses evident on radiographic findings.