Breast hypoechoic masses are the way the exam is reported when a breast ultrasound is performed. A normal breast gland under breast ultrasound is normally echogenic. If the breast ultrasound reveals a solid tissue mass with enhanced reflectivity to ultrasound, it will indicate a hypoechoic mass, such as breast fibroids, breast hyperplasia, or localized calcified lesions in the breast. If a hypoechoic mass is found on the mammogram it would indicate the presence of lesions within the breast that have low reflectivity to ultrasound, such as breast cysts and abscesses. Hypoechoic masses in the breast alone do not completely determine what the lesion is, and should be judged in conjunction with specific symptoms and physical signs, such as fever, breast pain, and often milk stagnation during lactation, which can mostly be judged as mastitis and abscess formation within the breast. So if you find a hypoechoic mass in the breast don’t be nervous, go to a regular hospital’s mammography clinic or general surgery clinic for a checkup to clarify the cause and then treat the problem.