Hello, I am 18 male, i discovered a rock hard ball or lump near my spine over a year and half ago just about when i got a back tattoo over my spine and back it did not bother me at first however now a year and a half later the lump still seems to be there i experienced weight loss of about 12 kilos in a span of 2 months however i ate as much and did no drastic change to my diet or exercise, now i have lower back ache quiet often more when i stand too long or sit for too long, the pain usually does not go away immediately however sitting on something soft and moving the spine around seems to help slightly also putting pressure on my lower back. What could this possibly be ?