Breast dysplasia in a 22-year-old girl is mainly manifested as flat chest, lack of breast glandular tissue, occurring unilaterally, the breast is asymmetrical, which can be accompanied by the same side of the pectoralis major muscle dysplasia or lack of. Causes of mammary gland dysplasia: 1, estrogen and progesterone decrease, mammary gland tissue does not get enough hormone stimulation and affects the development. 2, embryonic mammary gland tissue is not stimulated by the hormone. 2, the embryo when the breast tissue is poorly developed, affecting the growth and development of the mammary glands in the future. 3, girls excessive control of diet, the development of mammary glands is also affected. 4.Some girls bind their breasts, which will also limit the development of mammary glands. Treatment needs to go to the hospital for examination, to clarify the cause, through diet, massage or exercise breast enlargement, or breast augmentation surgery, for treatment. This increases the contents of the breast, improves the shape of the breast, enlarges the volume of the breast, and enables women to embody their characteristic curvaceous beauty. If a lump is found in a woman’s breast and the nature of the lump cannot be determined after breast ultrasound and mammogram, a puncture biopsy of the breast lump can be performed. Puncture biopsy of breast lumps is a method used to examine the pathological changes in the tissue cells and finally to make a pathological diagnosis. The hospitalization requirement for a breast lump biopsy varies from hospital to hospital, but most hospitals require that the patient be hospitalized and wait at home for the results of the biopsy cytology. If the pathological results of the puncture suggest that the breast tumor needs surgical treatment, then the patient needs to be hospitalized for surgical treatment, to remove the breast lesion, and to carry out pathological examination of the removed tumor to further clarify the nature of the tumor, so as to carry out the subsequent regular treatment.