Case 2 Answer
BI-RADS category 4, suspicious for malignancy. Pleomorphic microcalcifications are present in a segmental distribution in the lower outer left breast.
Recommendation: stereotactic core biopsy
Now, if you were convinced this were DCIS and wanted to call this a BI-RADS 5, highly suggestive of malignancy, that would be acceptable.
Many mammographers classify a lesion BI-RADS 5 if they are convinced that it is cancer. "I'll eat my hat if it's not cancer" (ie. >95% of their biopsies of BI-RADS 5 lesions are cancer.)
Others use category BI-RADS 5 in order to direct clinical decision making: they will recommend surgical excision even if a needle biopsy yields benign results. You can imagine there is a big overlap between these two ways of defining BI-RADS 5, but the latter mammographer may include lesions which have a larger likelihood of being benign, but still need to be removed (such as radial scars), and thus their biopsies of BI-RADS 5 lesions yields cancer in fewer cases (for example 75% of BI-RADS 5 lesions).