A solid nodule in the breast is actually the opposite of a cystic nodule, which is a diagnostic description of a test, or lump. Solid nodules are mostly hypoechoic or hyperechoic under ultrasound, or even partially mixed echogenic, but definitely not echogenic, with a tougher or harder texture, no elasticity, and in some cases, a little blood flow. Clinically common solid nodules are considered to be caused by cystic hyperplasia of the breast, or fibroadenoma of the breast, or possibly a tumor of the breast, such as breast cancer. For example, the clinical manifestations of cystic hyperplasia are menstrual-related breast pain, which is more severe before menstruation and less severe after menstruation. Fibroadenoma of the breast has no obvious symptoms, its surface is smoother and more mobile, and it does not change for a long time. Breast cancer is a painless, very poorly mobile, solid mass with an unsmooth surface, which can basically be clarified by mammogram.