<s>[INST] yes i had cancer in 2006,and in 2010 diagnose with lobular incarsinoma in citu not going through any chemo everything was fine until i started feeling a swollen lyphnode under my jaw but closest to my ear this occured in sept.did not tell my oncologist cause i went to the emergency that dr.looked into my mouth and says its caused by a bad tooth however my tooth doesnt hurt he knew my history why didnt he ask for blood work? [/INST] Hi,Reactive lymphnodes are commonest in most people. This is usually due to an infection. However, since you have had cancer in the past, it is necessary to be seen by your oncologist to make certain that it is only an infective cause. </s>