80yr old female, history of breast cancer with right side mastectomy , recently bumped right arm just above right elbow and at first asymptomatic . 2 days later entire right arm +2 pitting edema from upper mid arm to fingertips, right arm is also a dark purple and mid upper arm is firm to touch. Her radial pulse is +2 and her lower arm and hand is slightly cool to touch and upper arm is warm. She is very confused but does grimace with pain when manipulating right arm. recent xray of shoulder and elbow show nothing broken. Could a contusion to the upper arm region cause bleeding inside the arm that would turn the entire arm dark purple all the way to her fingertips. She is not on blood thinners of any kind.