I have a rubbery moveable lump around upper left abdomen muscles and rib,i can move it on the rib when i flex,its around 2cm,what could it be?

Possible lipoma : Possibly it is a fatty lump called lipoma It is benign If it bothers you it can be excised

Explanation : May be this is muscle spasm. Try massage it for a week and muscle pain cream. If it will persist more than 2 weeks, you need evaluation by a doctor.

Under muscles?: Is it under the skin or muscles? This could be a lipoma which is a common, not harmful fatty tumor. Any pain in area? Other symptoms?