With the convenient application of the Internet, many medical science knowledge can be searched through the Internet. However, medical science articles are of different quality and people’s medical background knowledge varies, some medical knowledge is quite difficult to understand, and even cause people to panic because of half-understanding. One of the medical terms that can easily cause nervousness among women is intra-mammary calcification foci. Some women often ask, “Doctor, I had a mammogram and the report indicates calcification, do I have breast cancer?” Next, we will talk about how calcified foci in the breast occur, how to check them, and which calcified foci are breast cancer or suspected breast cancer. Why are there calcified foci? Some doctors will describe it very graphically that calcified foci are like sprinkling some salt on the film. Don’t think this is just an analogy. In fact, calcified foci are really “salt” in the breast. The occurrence of calcification in breast tissue lesions is related to the degeneration of cells in the lesion, the deposition of calcium salts after necrosis, and the paracrine secretion of tumor cells and mammary gland cells. In layman’s terms, this means that the cells in the mammary gland become diseased, necrotic and form calcium salts, or they secrete some calcium salts themselves (for example, some cysts secrete calcium salts from the cyst wall cells). The occurrence of calcification in the non-focal breast tissue is related to the inflammatory damage of the local tissue and the deposition of calcium salts after the repair of the damage, which can be interpreted as the deposition of calcium salts during the healing process after the inflammation or injury of the breast tissue (e.g., trauma, surgery, etc.). Calcified foci are not palpable and, in many cases, are not detected by ultrasound or MRI. We know from the previous chapters that mammography is the best test to detect calcified foci. Many patients are very nervous about coming to the doctor because the word “calcification” appears on the report. When the doctor takes a look, the word “calcification” is preceded by the word “coarse”, and when he looks at the mammogram, there is just one calcified spot of about 2 mm in diameter appearing on the film. Then, congratulations to these people, this calcification foci are benign. Calcified foci are classified according to their diameter size as coarse calcifications (>0.5 mm in diameter) and microcalcifications (<0.5 mm in diameter). Coarse calcifications within or around the lump are usually seen in benign breast disease. Isolated coarse calcifications within the breast are commonly seen as calcium salt deposits following tissue injury and local necrosis. For example, aging arteries within the breast tissue, old surgical scars, and calcium salt deposits from cumulus cysts. In contrast, the presence of microcalcifications may be associated with the diagnosis of breast cancer. Whether the calcification is good or bad depends on the "appearance" of the calcification. It depends on the shape, size, number and density of calcification foci. In general, polymorphic and heterogeneous calcifications, linear or linear branching calcifications (cast calcifications) and clusters of microcalcifications are often suspected as malignant lesions. There is no need to panic when calcifications are found in the breast, as they are not always a sign of breast cancer. You only need to follow the guidance of your breast specialist and further clarify your condition with other imaging tests. For benign calcifications, close follow-up is sufficient, while for suspected malignant calcifications, a puncture biopsy or surgical excision is needed to clarify the diagnosis.