The differences between mammary gland hyperplasia and breast cancer include the nature of the disease, clinical manifestations, treatment, and prognosis, as follows: First, the nature of the disease: mammary gland hyperplasia is a benign disease, while breast cancer is a malignant disease. Secondly, clinical manifestation: most of the breast enlargement is painful and swollen at the time of menstruation, and the symptoms are relieved or disappear after the menstrual cycle. In contrast, breast cancer is usually a localized lump without any pain, mainly characterized by hard texture, unclear boundary and poor mobility. Treatment: Breast enlargement is usually treated conservatively without surgery, while breast cancer usually requires timely surgery and post-operative chemotherapy, radiotherapy, and even molecular targeted drugs. Prognosis: Breast hyperplasia has a good prognosis, while breast cancer has the risk of recurrence and metastasis after surgery and post-operative comprehensive treatment.