I had breast cancer in the left breast and had radiation since then (2010) I have this nagging pulse and slight thickening on the right side under my right rib.  I am over weight, I feel a hard lump in diagphram did ultra sounds, and ct it is not my liver or gall bladder.  Sometimes it stiffens and tightens
Hi. If the CT and ultrasound is normal this lumpish feeling may be just an inflammation of the underlying ribs or muscles. That is why it stiffens and tightens. Take an anti-inflammatory and you will be fine.