Hard lump below rt. ribcage for a yr. moves, pops up/dn between ribs. dr said could be many things. ct revealed it's in muscle surrounding rib. ideas?

Could be a torn musc: I would have prefer to see am MRI rather than ct, MRI much better for soft tissue diagnosis.Depending upon wich level of the ribs you are talking about several muscles are inserted on the ribs, more supirioly are the pectoralis, below are the insertion of the serratus, more infiriorly are the abdominal muscles etc, on the back different set of muscles and in between the ribs are the interscostal muscl.