This patient support community is for discussions relating to breast cancer, biopsy, genetics, chemotherapy, hormone therapy, lumps, lumpectomy, lymph node dissection, lymphedema, mammograms, mastectomy, radiation therapy, reconstruction, and self exams.
If the mammogram is suspicious of malignancy, the next step is biopsy, which you have undergone.
It is possible that a radiologically suspicious lesion turns out to be benign on core biopsy. Although it is theoretically possible that the biopsy missed the real lesion, and sampled only the adjoining tissue, this is unlikely because the mass is relatively big (1.3 cm) and 4 samples were cut. The clips placed within the breast will help in serial monitoring of the lesion on radiology.
Shoulder soreness is common after breast biopsy, but should rapidly subside. You need tro see your doctor if pain persists.