A large round nucleus in the center of the breast is generally a normal development phenomenon, but may also be caused by disease. 1. Normal development phenomenon: when the breasts of adolescent girls begin to develop, breast lumps and pain is a normal physiological phenomenon, usually does not need treatment. 2. Disease: Breast lumps in adult women may be due to endocrine hormone metabolism imbalance caused by breast hyperplasia nodules, a benign lesion caused by the normal development or degeneration process of the mammary gland, which is mainly manifested as breast pain, limited thickening of the gland or the formation of lumps, etc. There may also be mastitis, mammary gland pain, breast pain, breast pain, and breast cancer. It may also be caused by mastitis and breast tumor. Other conditions can also lead to a large round nucleus in the middle of the breast, it is recommended that the patient consult a doctor in time to clarify the cause of the disease and then under the guidance of the doctor for appropriate treatment.