<s>[INST] my 2 yr old son has a pea sized lump on the left side of his neck.  It is near the back of his neck about 2 inches from his collar bone. It seems to be stationary but will move if I press it.  He has had it about 3 weeks.  It doesn't appear to be painful.  Is this something I should worry about? [/INST] Hi.Not really to worry about as this is a lymph node most probably. A course of antibiotic and anti-inflammatory medicine under the guidance of a Pediatrician will heal it completely. There may have been a focus of infection in the scalp or so, would have been healed long ago. </s>