When palpating the breasts to see if there is a lump or a mass that will be a cause for alarm, look for a dominant breast mass.
One has to differentiate between lumpy or nodular breast surface and a true lump which is represented by a so-called dominant breast mass, in medical parlance.
Look at the diagram below on the difference.
A dominant breast mass is a three-dimensional distinct mass that is different from the surrounding breast tissue. If there is uncertainty whether a finding represents a true dominant mass, comparison with the mirror-image location in the opposite breast is recommended.
If a dominant breast mass is palpated, it is considered a red flag. A breast specialist should be consulted as soon as possible. The dominant breast mass needs further evaluation and investigation. It does not automatically mean it is cancer. It may still be benign. It has to be evaluated by a breast specialist.