Cording may happen after breast cancer surgery. Cording is Lymphatic vessels which attach to the scar, as the wound heals the fascia gets tighter as it goes down the arm. This gives the effect of a cord hence the name cording.
It looks like a guitar string, may feel uncomfortable and even painful. Generally, it restricts your range of movement e.g. putting your hands behind your head or brushing the back of your hair.
We usually take between 2 and 4 sessions for this to be resolved.