Too much activity
The symptoms and signs are consistent with too much activity, which results in bleeding, and then capsular contracture. It can be a coagulated vein that sometimes occurs after breast augmentation called Mondor's cord. There is nothing dangerous about it. I can be treated with aspirin, warm compressed and massage. The vein, which no longer has blood flowing through it, is now just a scar. The scar is only a problem because it causes constriction. I massage the scar out to break it into small segments of scar so that it no longer is painful and constricting.