First of all, we need to know what is the mammary gland, which is located between the superficial and deep layers of the superficial subcutaneous fascia of the human breast, the superficial fascia extends into the mammary tissue to form a strip of lobular intervals, one end is attached to the pectoral fascia, the other end is attached to the skin, fixing the mammary gland in the subcutaneous tissue of the breast; the breast gland consists of 15-20 lobes, each lobe is divided into several glandular lobules, each glandular lobule is composed of 10-100 glandular vesicles. The number (2-20) and location (on the abdomen or on the thorax) of the mammary glands varies from species to species, with most mammals having the nipple as the opening of the mammary gland, which has a certain number of milk duct openings, but only one milk duct leading to the storage cavity. So what is a mammary cyst? What is the difference between it and a tumor? What is a breast cyst? Breast cysts, also known as mastitis, are caused by the accumulation of milk in the breast due to the poor discharge of milk from one lobe during breastfeeding, and the main clinical manifestation is a swelling in the breast, which is often misdiagnosed as a breast tumor. Breast cysts are benign breast diseases, and benign breast lumps (or nodules) can be divided into: breast tissue hyperplasia, mastopathy and breast cystic disease in terms of pathological diagnosis. Among them, breast cystic disease mostly occurs in women aged 30 to 50 years old, especially in those who have not given birth; if the lesions are accompanied by atypical hyperplasia, there is a higher risk of cancer, and thus they are also considered precancerous. Many women are found to have breast lumps during health checkups or unintentionally, but whether they are benign or malignant requires further medical examination or observation. In fact, not all breast lumps are breast cancer, but may be breast cysts. The initial symptom of breast cyst is usually a breast mass, unilateral, located in the peripheral part of the breast outside the areola area, round or oval, with clear borders, smooth surface, slightly mobile, cystic to touch with mild tenderness, usually 2-3 cm in diameter, usually without axillary lymph node enlargement, and in young women who find a clearer breast mass during or after breastfeeding, and complain of having suffered from mastitis during breastfeeding, examined in the If a young woman finds a swelling with clear border and smooth surface outside the areola area, she should think about the possibility of breast cyst, and the diagnosis can be confirmed by ultrasound. What is a tumour? Tumour is a neoplasm formed by the proliferation of local tissue cells under the action of various tumorigenic factors. According to the cellular characteristics of the neoplasm and the degree of harm to the body, tumors are divided into two categories: benign tumors and malignant tumors, and cancer is the general term for malignant tumors. It should be noted that cancer and carcinoma are two different concepts. Cancer refers to epithelial malignant tumors, for example, malignant tumors formed by the mucosal epithelium of the colon are called colorectal mucosal epithelial carcinoma, or colorectal cancer for short. Those formed by skin epithelium are called skin epithelial cancer, or skin cancer for short, and so on. Therefore, if a doctor says that someone is suffering from cancer, it means that the patient has a malignant tumor; if he says that someone is suffering from gastric cancer, it means that the patient has cancer formed by the epithelium of gastric mucosa, if he says that the patient has gastric sarcoma, it means that this malignant tumor is not formed by the epithelial cells of mucosa, but may be caused by the malignant transformation of smooth muscle cells, or belongs to malignant lymphoma of stomach, etc.. However, it can also be said in general that he has cancer. The difference between breast cyst and tumor Breast cyst is also a kind of tumor but it is generally benign, there are benign and malignant tumors, this disease belongs to benign breast lesions. Once found, surgery should be considered to remove the cyst, and the surgery should only be performed to remove the cyst alone. If there is secondary infection during breastfeeding, the infection should be controlled and the milk should be returned and then the cyst should be removed and sent for disease examination.