Flocculent echoes in dilated mammary ducts may be caused by acute mastitis, or may be caused by neoplastic diseases, which should be promptly clarified by the next step in the examination to identify the cause of the disease and take the relevant treatment. 1. Acute mastitis: When a woman suffers from acute mastitis, the venous blood circulation of the mammary gland is prone to circulatory disorders, which can lead to blood stagnation in the blood vessels, which may make the blood vessels thicker and swollen, leading to an increase in the permeability of the blood vessels, which indirectly pulls the mammary ducts, resulting in dilated mammary ducts. 2. Neoplastic diseases: If the patient is older, flocculent echoes in the dilated breast ducts may be caused by neoplastic diseases, such as breast cancer, breast fibroadenoma, breast cysts and so on. When there is a neoplastic disease, the tumor will grow in the breast cells as well as in the breast ducts, and when it grows to a certain amount and forms a heterogeneous substance, it may dilate the breast ducts. In the case of dilated breast ducts with flocculent echoes, the cause of the disease should be identified and treated in a timely manner in order to avoid delaying the condition.