<s>[INST] My 2 year old son has a bruised soft bump seems to be covering a hard bump on his lower mid spine and has had it for at least 2 months now. I took him to the doctor when I first noticed it and she said it looked like it may have been slightly injured. It still hasnt gone away at all should I be concerned? [/INST] Hi... by what you got I feel that It could be a lipoma or as it is in the midline, it could also be a dermoid cyst.Though as  of now there are no neurological symptoms or weakness of the lower Limbs I suggest You consult your pediatrician and get an MRI spine done. I am suggesting this to rule out spinal pressure or spinal extension of the swelling.Regards - Dr. Sumanth </s>