Ten-year-old girl breast secretion yellowish fluid may be caused by intraductal papilloma, ductal inflammation, breast hyperplasia and other reasons. 1. Intraductal papilloma: the specific cause is not clear, may be related to drugs, food and other factors, may appear breast lumps, breast secretion of yellowish liquid and other symptoms, can be treated by surgical excision. 2. Mammary duct inflammation: generally due to the local inflammation caused by the mammary ducts are not smooth, there may be breast secretion of yellowish fluid, accompanied by local lumps, pain, fever, malaise and other symptoms, can be under the guidance of the doctor orally cefuroxime, cephradine and other drugs for treatment. 3. Mammary gland hyperplasia: it may be caused by endocrine disorders, there may be breast pain, breast secretion of yellowish fluid and other symptoms, can be treated with drugs such as clomiphene and tamoxifen. Therefore, ten-year-old girl breast secretion yellowish liquid, accompanied by pain, lumps and other uncomfortable symptoms, should go to the hospital as soon as possible, under the guidance of the doctor for standardized treatment.