Back and shoulder pain with tenderness and lump in chest

Ok lest see if I can describe this… My wife has been experiencing pain in the left side of her back/shoulder just inside her scapula. This pain is accompanied by pain and swelling (knot-like) in her chest just above the left breast. She describes the pain in her back as feeling like someone is jabbing her with a stick and tightness in the chest. The pain has been present for over a year now.
She says that the pain is worse if she does anything strenuous with the arm but the pain diminishes if she walks or is mildly active. She also states that the pain seems to get worse if she is inactive for any length of time.
She has been to the emergency room on at least four occasions where she was administered an EKG each time. The EKG has been normal each time. Blood tests have come back negative for anything cardio related. A biopsy was performed for the knot in her chest and it was determined the knot is benign.
She has gone through physical therapy prescribed by three different doctors, and pain meds and muscle relaxers prescribed do little to alleviate the pain.
Nobody seems to be able to identify the cause though her current doctor seems it is cause by a “loose rib” but treatments don’t seem to have any affect.
Kind of getting despaired here…