It would just be considered at benign finding in that case. They do occur normally within the breast tissue but when clustered they indicate the reaction of the breast tissue .... doesn't always mean cancer though. They are only tiny dots that sometimes group together in a pattern (cluster).
Microcalcifications can indeed be a sign of both benign or malignant breast lesions. The most common of the benign lesions would be that of fibrocystic breast diseases or fibroadenoma. In-situ tumors such as DCIS (ductal carcinoma in situ) is also a possibility, but thi is considered a pre-malignant condition (capable of developing into an invasive cancer in the future).
The overall characteristics of the calcifications would be taken into consideration by the radiologist who interpreted the mammogram, and based on his impression, he can request further testing to ascertain the nature of these findings.
Regards.