<s>[INST] MY 3 YR OLD SON HAS HAD A LUMP ON THE HIS NECK ABOUT AN INCH BEHIND HIS EAR JUST UNDER THE BASE OF HIS SKULL SINCE HE WAS 6 MONTHS OLD. IT HAS JUST RECENTLY BECAME A LITTLE LARGER. IT IS KIND OF FIRM AND ONLY MOVES A LITTLE.  IS IT NORMAL? I AM VERY CONCERNED [/INST] Hi, The lump behind the ear appears to be lymph node and is usually enlarged in infections. It would usually disappear on its own, once the infection is treated. Infection particularly in the scalp like Dan Chat Doctor.  If there is any ear discharge, ear infection can be thought of. Most probably the infection could be from scalp. If it persists even after scalp treatment for a longer time, fine needle aspiration test for the lump can be done. If you have any questions, happy to help again. </s>