<s>[INST] I have a hard marble sized lump on the upper right side of my back underneath the shoulder blade.  When I bend my arm and put it behind my back the lump can be felt.  This has been the source of my (muscular) back pain for about 6 years now.  I have had someone try to consistently rub it out for several days at a time with no result.  It just causes irritation and the lump stays the same size.  I have read around and thought that it may be a cyst.  Is this possible in an upper back muscle?  Not sure if this has any bearing, but I do not have a hairy back.  If this is a cyst, would surgery be required to remove it?...and what type of doctor would I need to see? Thank you for any answers. [/INST] Hi. Read your history and an elucidated explanation about the lump you have underneath the shoulder blade. This is there for 6 years and by doing massage or so, you must have troubled it more. The most probable cause for such a mass may be fibrotic lump at the joining of muscles and as such a result of the chronic stress injury syn Chat Doctor.  I would advise you to see the Orthopedic or General Surgeon for proper diagnosis and take assistance of ultrasonography to know the exact content of it and get treatment accordingly. If this is related to the tendons, local steroid injection will solve your problem. If this is a cyst, it can be excised, and you will get symptom free. </s>