my 23 yo son developed a 2 inch lump at the base of the skull just above the hairline. the lump is tender and red and directly in the center of his head where the spine ends.
no medical professional could make an accurate assessment/diagnosis based solely on a vague description. your son needs to have this lump carefully examined by a medical professional. it could be many different things. a sebaceous cyst a reactive post-occipital lymph node. or? please encourage him to do the right thing and have it properly examined and diagnosed.