Jump to Breast biopsy - Microcalcifications are not usually due to cancer. But a group of microcalcifications found in one area can sometimes be a sign of pre-cancerous changes or early breast cancer. You may need further tests to check for cancer cells. Tests may include a close-up mammogram and a breast biopsy. Because calcifications are so small, a computer and mammogram are usually used to locate them accurately so a biopsy can be taken from the affected area.