instruction: hi doctor I am having a mild tender bump or a lump or a kind of knot deep under the skin on the deltoid muscle it is very hard to tell if it is moving under the skin it has been there for three years I have not noticed any significant growth in the last three years I am quite scared after reading about sarcomas I am 20 years old please help
output: hi I can understand the anxiety you would be suffering from after suspecting that it is a sarcoma here is what I can suggest to you sarcoma is an uncommon cause of such lumps and much more common are some harmless cysts and lipomas malignant tumors like sarcoma generally do not stay the same size for three years most malignant sarcoma in limbs are not associated with pain however there is only one way to find out for sure and that is doing some tests on this lump you have not mentioned the size of the lump if it is small for about 2 am in diameter then it may be possible to take it out and test for malignant cells thoroughly if it is larger then an mri scan and a needle core biopsy can be done to decide the treatment whether it can directly be taken out or not will be decided by the size and exact location of the lump please send a picture with a scale measure by the side of the lump if you want to follow up much more commonly however it is a cyst that can be easily taken out without any ill effects to know if it is a cyst or not your doctor needs to examine you and maybe do an ray of the limb and an ultrasound examination of the site but only if required for now do not worry just see a good surgeon most likely it is a lipoma or a cyst and not a tumor