I have a knot? About the size of a popcorn seed, painless under skin in left leg in groin, crease of leg. I have back problems L1-L5 are all bad. But this "seed" is on front, and every once in a while my hip " gives out" with weight and i think its coming from my "seed" problem? Ive suffered with my back pain for 26 years, and this is different. Ive had MRI CTscan xrays all show nothing! Ugh i know what i feel isnt suppose to be there. Ive been refered to a surgeon, that i will be seeing tomorrow and asking for a ultrasound in that spot